First Claim

1. An anti-mitotic compound with a molecular weight of at least 150 grams per mole, a mitotic index factor of at least 10 percent, a positive magnetic susceptibility of at least 1,000×10−6 cgs, and a magnetic moment of at least 0.5 bohr magnetrons, wherein said compound is comprised of at least 7 carbon atoms and at least one inorganic atom with a positive magnetic susceptibility of at least 200×10−6 cgs.

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Abstract

An anti-mitotic compound with a molecular weight of at least 150 grams per mole, a mitotic index factor of at least 10 percent, a positive magnetic susceptibility of at least 1,000×10−6 cgs, and a magnetic moment of at least 0.5 bohr magnetrons. The compound contains at least 7 carbon atoms and at least one inorganic atom with a positive magnetic susceptibility of at least 200×10−6 cgs.

54 Claims

1. An anti-mitotic compound with a molecular weight of at least 150 grams per mole, a mitotic index factor of at least 10 percent, a positive magnetic susceptibility of at least 1,000×10−6 cgs, and a magnetic moment of at least 0.5 bohr magnetrons, wherein said compound is comprised of at least 7 carbon atoms and at least one inorganic atom with a positive magnetic susceptibility of at least 200×10−6 cgs.

2. The anti-mitotic compound as recited in claim 1, wherein said compound has a mitotic index factor of at least 20 percent.

3. The anti-mitotic compound as recited in claim 1, wherein said compound has a positive magnetic susceptibility of at least 5,000×10 −6 cgs.

4. The anti-mitotic compound as recited in claim 1, wherein said compound is comprised of at least 10 carbon atoms.

5. The anti-mitoitc compound as recited in claim 1, wherein said inorganic atom is radioactive.

6. The anti-mitotic compound as recited in claim 1, wherin said inorganic atom has a magnetic moment of at least 1.0 bohr magnetron.

7. The anti-mitotic compound as recited in claim 1, wherein said compound has a mitotic index factor of at least about 50 percent.

8. The anti-mitotic compound as recited in claim 7, wherein said compound has a positive magnetic susceptibility of at least 10,000×10−6 cgs.

9. The anti-mitotic compound as recited in claim 8, wherein said inorganic atom has a magnetic moment of at least 2.0 bohr magnetrons.

10. A composition comprised of the anti-mitotic compound of claim 1 and a polymeric material.

11. The composition as recited in claim 10, wherein said polymeric material is absorbable in living tissue.

12. The composition as recited in claim 10, wherein said polymeric material is selected from the group consisting of a silicon-containing polymeric material and a hydrocarbon-containing polymeric material.

13. The composition as recited in claim 10, wherein wherein said polymeric material is silicone rubber.

14. The composition as recited in claim 13, wherein said silicone rubber is dimethylpolysiloxane rubber.

15. The composition as recited in claim 13, wherein said silicone rubber is a biocompatible silicone rubber.

16. The composition as recited in claim 10, wherein said polymeric material is a synthetic absorbable copolymer formed by copolymereizing glycolide with trimethylene carbonate.

17. The composition as recited in claim 10, wherein said polymeric material is selected from the group consisting of polyester, polytetrafluoroethylene, polyurethane silicone-based material, and polyamide.

18. The composition as recited in claim 10, wherein said polymeric material is a copolymer containing carbonate repeat units and ester repeat units 19. The composition as recited in claim 10, wherein said polymeric material is collagen.

20. The composition as recited in claim 10, wherein said polymeric material selected from the group consisting of homopolymers and copolymers of glycolic acid and lactic acid.

21. The composition as recited in claim 10, wherein said polymeric material is comprised of a polycarbonate-containing polymer.

22. The composition as recited in claim 10, wherein said polymeric material is selected from the group consisting of polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acid, polyamides, and copolyesters of polyamides and polyestes.

23. The composition as recited in claim 10, wherein said polymeric material is selected from the group consisting of polyesters, polyamides, polyurethanes, and polyanhydrides.

24. A compositon comprised of a polymeric material and a compound with a molecular weight of at least 150 grams per mole, a positive magnetic susceptibility of at least 1,000×10−6 cgs, and a magnetic moment of at least 0.5 bohr magnetrons, wherein said compound is comprised of at least 7 carbon atoms and at least one inorganic atom with a positive magnetic susceptibility of at least 200×10−6 cgs.

25. The composition as recited in claim 10, wherein wherein said polymeric material is a poly (phosphoester).

26. The composition as recited in claim 10, wherein said anti-mitotic compound is bound within said polymeric material.

27. The composition as recited in claim 10, wherein a multiplicity of said anti-mitotic compounds are dispoed within said polymeric material.

28. The composition as recited in claim 10, wherein said polymeric material is a polypeptide.

29. The composition as recited in claim 10, wherein said polymeric material forms a reservoir within which is disposed said anti-mitotic compound.

30. The composition as recited in claim 29, wherein said reservoir is formed by a polymer selected from the group consisting of polyurethanes and its copolymers, silicone and its copolymers, ethylene vinylacetat, thermoplastic elastomers, polyvinylchloride, polyolefins, cellulosics, polyamides, polytetrafluoroethylenes, polyesters, polycarbonates, polysulfones, acrylics, and acrylonitrile butadiene styrene copolymers.

35. The composition as recited in claim 10, wherein a heterobifunctional photolytic linker is bonded to said polymeric material.

36. The composition as recited in claim 35, wherein said heterobifunctional photolytic linker is bonded to said anti-mitotic compound.

37. An assembly comprised of the composition of claim 36 and means for releasing said anti-mitotic compound from said heterobifuncitonal photolytic linker.

38. The assembly as recited in claim 37, wherein said means for releasing said anti-mitotic compound from said heterobifunctional photolytic linker comprises a first coherent laser light source.

39. The composition as recited in claim 10, wherein wherein said coherent laser light source provides coherent light with a wavelength of from about 280 to about 400 nanometers.

40. The anti-mitotic compound as recited in claim 1, wherein said anti-mitotic compound is disposed within a microcapsule.

41. The composition as recited in claim 10, wherein said polymeric material is a mixture of fibrinogen and thrombin.

42. The therapeutic assembly as recited in claim 10, wherein said polymeric material is a multi-layered polymeric material.

43. The composition as recited in claim 10, wherein said polymeric material is a porous polymeric material.

44. The composition as recited in claim 10, wherein said polymeric material has a thermal processing temperature of less than about 100 degrees Celsius.,

45. The composition as recited in claim 10, wherein said polymeric material is comprised of a porosigen.

46. The composition as recited in claim 45, wherein said porosigen is selected from the group of microgranules of sodium chloride, lactose, sodium heparin, polyethyelen glycol, polyethylene oxide/polypropylene oxide copolymer, and mixtures thereof.

47. The composition as recited in claim 10, wherein said polymeric material is a thermoplastic polymer.

48. The composition as recited in claim 10, wherein said polymeric material is an elastomeric polymer.

49. The composition as recited in claim 10, wherein said polymeric material is a controlled release polymer.

50. The composition as recited in claim 10, wherein said polymeric material is a transparent polymeric material.

51. The composition as recited in claim 10, wherein said polymeric material is a hydrophobic elastomeric material.

52. The composition as recited in claim 10, wherein said polymeric material is a hydrophilic polymer.

53. The composition as recited in claim 10, wherein said polymeric material is a temperature-sensitive polymer.

54. The composition as recited in claim 10, wherein said polymeric material is a thermogelling polymer.

55. The composition as recited in claim 54, wherein said thermogelling polymer is selected from the group consisting of poly(-methyl-N-n-propylacrlamide), poly(-methyl-N-n-propylacrylamide), poly(N-n-propylacrylamide), poly(N-methyl-N-isopropylacrylamide), poly(N-n-propylmethacrylamide), poly(N-isopropylacrylaminde),;

1 Specification

Cross

This application claims priority from United States provisional patent application U.S. Ser. No. 60/516,134, filed on Oct. 31, 2003, the entire disclosure of which is hereby incorporated by reference into this specification.

This application is a continuation-in-part of applicants' U.S. patent application Ser. No. 10/808,618, filed on Mar. 24, 2004, and of applicants' U.S. patent application Ser. No. 10/867,517, filed on Jun. 14, 2004.

FIELD OF THE INVENTION

An anti-mitotic compound with a mitotic index factor of at least 10 percent, a positive magnetic susceptibility of at least 1,000×10<sup>−6 </sup>cgs, and a magnetic moment of at least 0.5 bohr magnetrons per molecule of said compound.

BACKGROUND OF THE INVENTION

Tubulin-targeting drugs are well known to those skilled in the art. They are described, eg., in Chapter 5 of John M. Kirkwood et al.'s “Current Cancer Therapies,” Fourth Edition (Current Medicine, Inc., Philadelphia, Pa., 2001). At page 95 of such book, it is disclosed that: “Tubulins have a central role in eukaryotic biology . . . Microtubules are hollow cylinders comprised of tubulin . . . Microtubules are also crucial during both mitosis and meiosis, accurately segregating chromosomes to the two daughter cells by forming a complex super-structure called the mitotic spindle.”

Drugs that target the tubulin moiety of microtubules, such as the taxanes, have been used as anti-cancer agents. The taxanes “ . . . target a separate site, binding primarily to the amino-terminal 31 amino acids of the beta-tubulin subunit . . . ,” as is disclosed at page 96 of the Kirwood et al. text. Reference also may be had to an article by K. H. Downing entitled “Structural basis for the interaction of tubulin with protein and drugs that affect microtubule function” (Annu Rev Cell Devel Biol 2000, 16:89-11). These taxanes “ . . . stabilize microtubules against depolymerization by altering the tubulin rate dissociation constants at both ends . . . ” (see page 96 of the Kirkwood et al. reference).

A significant problem with prior-art tubulin targeting drugs is that normal cells, as well as cancer cells, are susceptible to the drug's effects. The drug thus kills both types of cells; the cure is often as bad as the disease.

It is an object of the present invention to provide an improved class of tubulin-targeting drugs that can be selectively delivered to cancer cells.

SUMMARY OF THE INVENTION

In accordance with this invention, there is provided an anti-mitotic compound with a molecular weight of at least 150 grams per mole, a mitotic index factor of at least 10 percent, a positive magnetic susceptibility of at least 1,000×10<sup>−6 </sup>cgs, and a magnetic moment of at least 0.5 bohr magnetrons per molecule of said compound. This compound is comprised of at least 7 carbon atoms and at least one inorganic atom with a positive magnetic susceptibility of at least 200×10<sup>−6 </sup>cgs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred compound of this invention is an anti-mitotic compounds. Such anti-mitotic compounds are known to those skilled in the art. Reference may be had, e.g., to U.S. Pat. Nos. 6,723,858 (estrogenic compounds as anti-mitotic agents), 6,528,676 (estrogenic compounds as anti-mitotic agents), 6,350,777 (anti-mitotic agents which inhibit tubulin polyumerization), 6,162,930 (anti-mitotic agents which inhibit tubulin polymerization), 5,892,069 (estrogenic compounds as anti-mitotic agents), 5,886,025 (anti-mitotic agents which inhibit tubulin polymerization), 5,661,143 (estrogenic compounds as anti-mitotic agents), 3,997,506 (anti-mitotic derivatives of thiocolchicine), and the like. The entire disclosure of each of these United States patents applications is hereby incorporated by reference into this specification.

These prior art anti-mitotic agents may be modified, in accordance with the process of this invention, to make them “magnetic,” as that term is defined in this specification. In the next section of this specification, a process for modifying prior art taxanes to make them “magnetic” is described.

Preparation and Use of Magnetic Taxanes

In this portion of the specification, applicant will describe the preparation of certain magnetic taxanes that may be used in one or more of the processes of his invention.

In one embodiment of the invention, a biologically active substrate is linked to a magnetic carrier particle. An external magnetic field may then be used to increase the concentration of a magnetically linked drug at a predetermined location.<chemistry id="CHEM-US-00001" num="1"><img id="EMI-C00001" he="5.42mm" wi="40.39mm" file="US20050095197A1-20050505-C00001.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

One method for the introduction of a magnetic carrier particle involves the linking of a drug with a magnetic carrier. While some naturally occurring drugs inherently carry magnetic particles (ferrimycin, albomycin, salmycin, etc.), it is more common to generate a synthetic analog of the target drug and attach the magnetic carrier through a linker.

Functionalized Taxanes

Paclitaxel and docetaxel are members of the taxane family of compounds. A variety of taxanes have been isolated from the bark and needles of various yew trees.

In one embodiment of the invention, such a linker is covalently attached to at least one of the positions in taxane.<chemistry id="CHEM-US-00002" num="2"><img id="EMI-C00002" he="128.95mm" wi="58.67mm" file="US20050095197A1-20050505-C00002.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

It is well known in the art that the northern hemisphere of taxanes has been altered without significant impact on the biological activity of the drug. Reference may be had to Chapter 15 of Taxane Anticancer Agents, Basic Science and Current Status, edited by G. George et al., ACS Symposium Series 583, 207<sup>th </sup>National Meeting of the American Chemical Society, San Diego, Calif. (1994). Specifically the C-7, C-9, and C-10 positions of paclitaxel have been significantly altered without degrading the biological activity of the parent compound. Likewise the C-4 position appears to play only a minor role. The oxetane ring at C-4 to C-5 has been shown to be critical to biological activity. Likewise, certain functional groups on the C-13 sidechain have been shown to be of particular importance.

In one embodiment of the invention, a position within paclitaxel is functionalized to link a magnetic carrier particle. A number of suitable positions are presented below. It should be understood that paclitaxel is illustrated in the figures below, but other taxane analogs may also be employed.<chemistry id="CHEM-US-00003" num="3"><img id="EMI-C00003" he="219.71mm" wi="74.76mm" file="US20050095197A1-20050505-C00003.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry><chemistry id="CHEM-US-00004" num="4"><img id="EMI-C00004" he="85.17mm" wi="64.77mm" file="US20050095197A1-20050505-C00004.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>Attachment at C-4

C-4 taxane analogs have been previously generated in the art. A wide range of methodologies exist for the introduction of a variety of substituents at the C-4 position. By way of illustration, reference may be had to “Synthesis and Biological Evaluation of Novel C-4 Aziridine-Bearing Paclitaxel Analogs” by S. Chen et al., J. Med. Chem. 1995, vol 38, pp 2263.<chemistry id="CHEM-US-00005" num="5"><img id="EMI-C00005" he="90.00mm" wi="138.18mm" file="US20050095197A1-20050505-C00005.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

The secondary (C-13) and tertiary (C-1) alcohols of 7-TES baccatin were protected using the procedure of Chen (J. Org. Chem. 1994, vol 59, p 6156) while simultaneously unmasking the alcohol at C-4. The resulting product was treated with a chloroformate to yield the corresponding carboxylate. Removal of the silyl protecting groups at C-1, C-7, and C-13, followed by selective re-protection of the C-7 position gave the desired activated carboxylate. The compound was then treated with a suitable nucleophile (in the author's case, ethanolamine) to produce a C-4 functionalized taxane. The C-13 sidechain was installed using standard lactam methodology.

This synthetic scheme thus provides access to a variety of C-4 taxane analogs by simply altering the nucleophile used. In one embodiment of the instant invention, the nucleophile is selected so as to allow the attachment of a magnetic carrier to the C-4 position.

Attachment at C-7

The C-7 position is readily accessed by the procedures taught in U.S. Pat. No. 6,610,860. The alcohol at the C-10 position of 10-deacetylbaccatin III was selectively protected. The resulting product was then allowed to react with an acid halide to produce the corresponding ester by selectively acylating the C-7 position over the C-13 alcohol. Standard lactam methodology allowed the installation of the C-13 sidechain. In another embodiment, baccatin III, as opposed to its deacylated analog, is used as the starting material.<chemistry id="CHEM-US-00006" num="6"><img id="EMI-C00006" he="127.68mm" wi="72.47mm" file="US20050095197A1-20050505-C00006.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

Other C-7 taxane analogs are disclosed in U.S. Pat. Nos. 6,610,860; 6,359,154; and 6,673,833, the contents of which are hereby incorporated by reference.

Attachment at C-9

It has been established that the C-9 carbonyl of paclitaxel is relatively chemically inaccessible, although there are exceptions (see, for example, Tetrahedron Lett. Vol 35, p 4999). However, scientists gained access to C-9 analogs when 13-acetyl-9-dihydrobaccatin III was isolated from Taxus candidensis (see J. Nat. Products, 1992, vol 55, p 55 and Tetrahedron Lett. 1992, vol 33, p 5173). This triol is currently used to provide access to a variety of such C-9 analogues.

In chapter 20 of Taxane Anticancer Agents, Basic Science and Current Status, (edited by G. George et al., ACS Symposium Series 583, 207<sup>th </sup>National Meeting of the American Chemical Society, San Diego, Calif. (1994)) Klein describes a number of C-7/C-9 taxane analogs. One of routes discussed by Klein begins with the selective deacylation of 13-acetyl-9-dihydrobaccatin III, followed by the selective protection of the C7 alcohol as the silyl ether. A standard lactam coupling introduced the C-13 sidechain. The alcohols at C-7 and C-9 were sufficiently differentiated to allow a wide range of analogs to be generated. “In contrast to the sensitivity of the C-9 carbonyl series under basic conditions, the 9(R)-dihydro system can be treated directly with strong base in order to alkylate the C-7 and/or the C-9 hydroxyl groups.”<chemistry id="CHEM-US-00007" num="7"><img id="EMI-C00007" he="82.97mm" wi="135.04mm" file="US20050095197A1-20050505-C00007.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

One skilled in the art may adapt Klein's general procedures to install a variety of magnetic carriers at these positions. Such minor adaptations are routine for those skilled in the art.

Attachment at C-7 and C-9

Klein also describes a procedure wherein 13-acetyl-9-dihydrobaccatin III is converted to 9-dihydrotaxol. Reference may be had to “Synthesis of 9-Dihydrotaxol: a Novel Bioactive Taxane” by L. L. Klein in Tetrahedron Lett. Vol 34, pp 2047-2050. An intermediate in this synthetic pathway is the dimethylketal of 9-dihydrotaxol.<chemistry id="CHEM-US-00008" num="8"><img id="EMI-C00008" he="75.01mm" wi="72.98mm" file="US20050095197A1-20050505-C00008.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

In one embodiment, the procedure of Klein is followed with a carbonyl compound other than acetone to bind a wide variety of groups to the subject ketal. Supplemental discussion of C-9 analogs is found in “Synthesis of 9-Deoxotaxane Analogs” by L. L. Klein in Tetrahedron Lett. Vol 35, p 4707 (1994).

Attachment at C-10

In one embodiment of the invention, the C-10 position is functionalized using the procedure disclosed in U.S. Pat. No. 6,638,973. This patent teaches the synthesis of paclitaxel analogs that vary at the C-10 position. A sample of 10-deacetylbaccatin m was acylated by treatment with propionic anhydride. The C-13 sidechain was attached using standard lactam methodology after first performing a selective protection of the secondary alcohol at the C-7 position. In one embodiment of the invention, this procedure is adapted to allow access to a variety of C-10 analogues of paclitaxel.<chemistry id="CHEM-US-00009" num="9"><img id="EMI-C00009" he="117.69mm" wi="72.73mm" file="US20050095197A1-20050505-C00009.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

In one embodiment an anhydride is used as an electrophile. In another embodiment, an acid halide is used. As would be apparent to one of ordinary skill in the art, a variety of electrophiles could be employed.<chemistry id="CHEM-US-00010" num="10"><img id="EMI-C00010" he="34.04mm" wi="64.43mm" file="US20050095197A1-20050505-C00010.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>Siderophores

In one embodiment, a member of the taxane family of compounds is attached to a magnetic carrier particle. Suitable carrier particles include siderophores (both iron and non-iron containing), nitroxides, as well as other magnetic carriers.

Sidephores are a class of compounds that act as chelating agents for various metals. Most organisms use sidephores to chelate iron (III) although other metals may be exchanged for iron (see, for example, Exchange of Iron by Gallium in Siderophores by Emergy, Biochemistry 1986, vol 25, pages 4629-4633). Most of the siderophores known to date are either catecholates or hydroxamic acids.<chemistry id="CHEM-US-00011" num="11"><img id="EMI-C00011" he="64.60mm" wi="36.83mm" file="US20050095197A1-20050505-C00011.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

In “Total Synthesis of Desferrisalmycin” (M. J. Miller et al. in J. Am. Chem. Soc. 2002, vol 124 pp 15001-15005), a natural product is synthesized that contains a siderophore. The author states “siderophores are functionally defined as low molecular mass molecules which acquire iron (III) from the environment and transport it into microganisms. Because of the significant roles they play in the active transport of physiologically essentially iron (III) through microbe cell members, it is not surprising that siderophores-drug conjugates are attracting more and more attention from both medicinal chemists and clinical researchers as novel drug delivery systems in the war against microbial infections, especially in an area of widespread emergency of multidrug-resistance (MDR) strains. There have been three families of compounds identified as natural siderophore-drug conjugates, including ferrimycin, albomycin, and salmycin.” In a related paper, Miller describes the use of siderophores as drug delivery agents (Acc. Chem. Res. 1993, vol 26, pp 241-249. Presumably, the siderophore acts as a “sequestering agents [to] facilitate the active transport of chelated iron into cells where, by modification, reduction, or siderophore decomposition, it is released for use by the cell.” Miller describes the process of tethering a drug to a sidrophore to promote the active transport of the drug across the cell membrane.

In “The Preparation of a Fully Differentiated ‘Multiwarhead’ Sidrophore Precursor”, by M. J. Miller et al (J. Org. Chem. 2003, vol 68, pp 191-194) a precursor is disclosed which allows for a drug to be tethered to a sidrophore. In one embodiment, the route disclosed by Miller is employed to provide a variety of siderophores of similar structure. The synthesis of similar hydroxamic acid-based siderophores is discussed in J. Org. Chem. 2000, vol 65 (Total Synthesis of the Siderophore Danoxainine by M. J. Miller et al.), pp 4833-4838 and in the J. of Med. Chem. 1991, vol 32, pp 968-978 (by M. J. Miller et al.).

A variety of fluorescent labels have been attached to ferrichrome analogues in “Modular Fluorescent-Labeled Siderophore Analogues” by A. Shanzer et al. in J. Med. Chem. 1998, vol 41, 1671-1678. The authors have developed a general methodology for such attachments.<chemistry id="CHEM-US-00014" num="14"><img id="EMI-C00014" he="34.37mm" wi="74.76mm" file="US20050095197A1-20050505-C00014.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

As discussed above, functionalized ferrichrome analogs have been previous generated, usually using basic amine acids (glycine). In one embodiment, functionality is introduced using an alternative amine acid (such as serine) in place of the central glycine residue. This provides a functional group foothold from which to base a wide variety of analogs. Using traditional synthetic techniques, various linkers are utilized so as to increase or decrease the distance between the magnetic carrier and the drug.<chemistry id="CHEM-US-00015" num="15"><img id="EMI-C00015" he="104.90mm" wi="46.31mm" file="US20050095197A1-20050505-C00015.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

As would be apparent to one of ordinary skill in the art, the above specified techniques are widely applicable to a variety of substrates. By way of illustration, and not limitation, a number of magnetic taxanes are shown below.<chemistry id="CHEM-US-00016" num="16"><img id="EMI-C00016" he="183.56mm" wi="72.81mm" file="US20050095197A1-20050505-C00016.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry><chemistry id="CHEM-US-00017" num="17"><img id="EMI-C00017" he="189.74mm" wi="84.92mm" file="US20050095197A1-20050505-C00017.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>Nitroxides

Another class of magnetic carriers is the nitroxyl radicals (also known as nitroxides). Nitroxyl radicals a “persistent” radials that are unusually stable. A wide variety of nitroxyls are commercially available. Their paramagnetic nature allows them to be used as spin labels and spin probes.<chemistry id="CHEM-US-00018" num="18"><img id="EMI-C00018" he="102.19mm" wi="54.10mm" file="US20050095197A1-20050505-C00018.TIF" alt="embedded image" img-content="chem" img-format="tif"/></chemistry>

The prior disclosure illustrates how one may modify prior art taxanes to make them magnetic. As will be apparent to those skilled in the art, one may similarly modify other modifiable prior art anti-mitotic compounds to make them magnetic.

Other modifiable prior art compounds

Many anti-mitotic compounds that may be modified in accordance with the process of this invention are described in the patent literature.

By way of further illustration, and referring to U.S. Pat. Nos. 5,504,074, 5,661,143, 5,892,069, 6,528,676, and 6,723,858 (the entire disclosure of each of which is hereby incorporated by reference into this specification), one may modify estradiol and estradiol metabolites to make them magnetic in accordance with the process of this invention. As is disclosed in U.S. Pat. No. 6,723,858 (the entire disclosure of which is hereby incorporated by reference into this specification, “Cell mitosis is a multi-step process that includes cell division and replication (Alberts, B. et al. In The Cell, pp. 652-661 (1989); Stryer, E. Biochemistry (1988)). Mitosis is characterized by the intracellular movement and segregation of organelles, including mitotic spindles and chromosomes. Organelle movement and segregation are facilitated by the polymerization of the cell protein tubulin. Microtubules are formed from alpha. and B tubulin polymerization and the hydrolysis of guanosine triphosphate (GTP). Microtubule formation is important for cell mitosis, cell locomotion, and the movement of highly specialized cell structures such as cilia and flagella.”

As is also disclosed in U.S. Pat. No. 6,723,858, “Microtubules are extremely labile structures that are sensitive to a variety of chemically unrelated anti-mitotic drugs. For example, colchicine and nocadazole are anti-mitotic drugs that bind tubulin and inhibit tubulin polymerization (Stryer, E. Biochemistry (1988)). When used Cell mitosis is a multi-step process that includes cell division and replication (Alberts, B. et al. In The Cell, pp. 652-661 (1989); Stryer, E. Biochemistry (1988)). Mitosis is characterized by the intracellular movement and segregation of organelles, including mitotic spindles and chromosomes. Organelle movement and segregation are facilitated by the polymerization of the cell protein tubulin. Microtubules are formed from alpha. and β tubulin polymerization and the hydrolysis of guanosine triphosphate (GTP). Microtubule formation is important for cell mitosis, cell locomotion, and the movement of highly specialized cell structures such as cilia and flagella. Microtubules are extremely labile structures that are sensitive to a variety of chemically unrelated anti-mitotic drugs. For example, colchicine and nocadazole are anti-mitotic drugs that bind tubulin and inhibit tubulin polymerization (Stryer, E. Biochemistry (1988)). When used alone or in combination with other therapeutic drugs, colchicine may be used to treat cancer (WO-9303729-A, published Mar. 4, 1993; J 03240726-A, published Oct. 28, 1991), alter neuromuscular function, change blood pressure, increase sensitivity to compounds affecting sympathetic neuron function, depress respiration, and relieve gout (Physician's Desk Reference, Vol. 47, p. 1487, (1993)).”

The term “anti-microtubule,” as used in this specification (and in the specification of U.S. Pat. No. 6,689,803), refers to any “ . . . protein, peptide, chemical, or other molecule which impairs the function of microtubules, for example, through the prevention or stabilization of polymerization. A wide variety of methods may be utilized to determine the anti-microtubule activity of a particular compound, including for example, assays described by Smith et al. (Cancer Lett 79(2):213-219, 1994) and Mooberry et al., (Cancer Lett. 96(2):261-266, 1995);” see, e.g., lines 13-21 of column 14 of U.S. Pat. No. 6,689,803. One preferred method, utilizing the anti-mitotic factor, is described in this specification.

By way of yet further illustration, one may use one or more of the anti-mitotic agents disclosed in U.S. Pat. Nos. 6,673,937 (syntheses and methods of use of new antimitotic agents), 6,624,317 (taxoid conjugates as antimitotoic and antitumor agents), 6,593,334 (camptothecin-taxoid conjugates as antimitotic and antitumor agents), 6,593,321 (2-alkoxyestradiiol analogs with antiproliferative and antimitotic activity), 6,569,870 (fluorinated quinolones as antimitotic and antitumor agent), 6,528,489 (mycotoxin derivatives as antimitotic agents), 6,392,055 (synthesis and biological evaluation of analogs of the antimitotic marine natural product curacin A), 6,127,377 (vinka alkaloid antimitotic halogenated derivatives), 5,695,950 (method of screening for antimitotic compounds using the cdc25 tyrosine phosphatase), 5,620,985 (antimitotic binary alkaloid derivatives from catharanthus roseus), 5,294,538 (method of screening for antimitotic compounds using the CDC tyrosine phosphatase), and the like. The entire disclosure of each of these United States patents is hereby incorporated by reference into this specification.

As will be apparent, one or more of the aforementioned anti-mitotic and/or anti-microtubule agents may be modified to make them magnetic in accordance with this invention.

Properties of the Preferred Anti-Mitotic Compounds

In one preferred embodiment, the compound of this invention has a mitotic index factor of at least about 10 percent and, more preferably, at least about 20 percent. In one aspect of this embodiment, the mitotic index factor is at least about 30 percent. In another embodiment, the mitotic index factor is at least about 50 percent.

As is known to those skilled in the art, the mitotic index is a measure of the extent of mitosis. Reference may be had, e.g., to U.S. Pat. Nos. 5,262,409 (binary tumor therapy), 5,443,962 (methods of indentifying inhibitors of cdc25 phosphatase), 5,744,300 (methods and reagents for the indentificatioin and regulation of senescence-related genes), 6,613,318, 6,251,585 (assay and reagents for indentifying anti-proliferative agents), 6,252,058 (sequences for targeting metastatic cells), 6,387,642 (method for indentifying a reagent that modulates Myt1 activity), 6,413,735 (method of screening for a modulator of angiogenesis), 6,531,479 (anti-cancer compounds), 6,599,694 (method of characterizing potential therapeutics by determining cell-cell interactions), 6,620,403 (in vivo chemosensitivity screen for human tumors), 6,699,854 (anti-cancer compounds), 6,743,576 (database system for predictive cellular bioinformatics), and the like. The entire disclosure of each of these United States patents is hereby incorporated by reference into this specification.

Reference may also be had, e.g., to U.S. Pat. No. 5,262,409, which discloses that: Determination of mitotic index: For testing mitotic blockage with nocodazole and taxol, cells were grown a minimum of 16 hours on polylysinecoated glass coverslips before drug treatment. Cells were fixed at intervals, stained with antibodies to detect lamin B, and counterstained with propidium iodide to assay chromosome condensation. To test cell cycle blocks in interphase, cells were synchronized in mitosis by addition of nocodazole (Sigma Chemical Co.) to a final concentration of 0.05 μg/ml from a 1 mg/ml stock in dimethylsulfoxide. After 12 hours arrest, the mitotic subpopulation was isolated by shakeoff from the culture plate. After applying cell cycle blocking drugs and/or 2-AP, cells were fixed at intervals, prepared for indirect immunofluorescence with anti-tubulin antibodies, and counterstained with propidium iodide. All data timepoints represent averages of three counts of greater than 150 cells each. Standard deviation was never more than 1.5% on the ordinate scale.”

Reference may be had, e.g., to U.S. Pat. No. 6,413,735 which discloses that: “The mitotic index is determined according to procedures standard in the art. Keram et al., Cancer Genet. Cytogenet. 55:235 (1991). Harvested cells are fixed in methanol:acetic acid (3:1, v:v), counted, and resuspended at 106 cells/ml in fixative. Ten microliters of this suspension is placed on a slide, dried, and treated with Giemsa stain. The cells in metaphase are counted under a light microscope, and the mitotic index is calculated by dividing the number of metaphase cells by the total number of cells on the slide. Statistical analysis of comparisons of mitotic indices is performed using the 2-sided paired t-test.”

By means of yet further illustration, one may measure the mitotic index by means of the procedures described in, e.g., articles by Keila Torres et al. (“Mechanisms of Taxol-Induced Cell Death are Concentration Dependent,” Cancer Research 58, 3620-3626, Aug. 15, 1998), and Jie-Gung Chen et al. (“Differential Mitosis Responses to Microtubule-stabilizing and destablilizng Drugs,” Cancer Research 62, 1935-1938, Apr. 1, 2002).

The mitotic index is preferably measured by using the well-known HeLa cell lines. As is known to those skilled in the art, HeLa cells are cells that have been derived from a human carcinoma of the cervix from a patient named Henrietta Lack; the cells have been maintained in tissued culture since 1953.

Hela cells are described, e.g., in U.S. Pat. Nos. 5,811,282 (cell lines useful for detection of human immunodeficiency virus), 5,376,525 (method for the detectioin of mycoplasma), 6,143,512, 6,326,196, 6,365,394 (cell lines and constructs useful in production of E-1 deleted adenoviruses), 6,440,658 (assay method for determining effect on aenovirus infection of Hela cells), 6,461,809 (method of improving infectivity of cells for viruses), 6,596,535, 6,605,426, 6,610,493 (screening compounds for the ability to alter the production of amyloid-beta-peptide), 6,699,851 (cytotoxic compounds and their use), and the like; the entire disclosure of each of these United States patents is hereby incorporated by reference into this specification. By way of illustration, U.S. Pat. No. 6,440,658 This patent discloses that, for the experiments described in such patent, “The HeLa cell line was obtained from the American Type Culture Collection, Manassas Va.”

In one preferred embodiment, the mitotic index of a “control cell line” (i.e., one that omits that drug to be tested) and of a cell line that includes 50 nanomoles of such drug per liter of the cell line are determined and compared. The “mitotic index factor” is equal to (Mt−Mc/Mc)×100, wherein Mc is the mitotic index of the “control cell line,” and Mt is the mitotic index of the cell line that includes the drug to be tested.

The compound of this invention preferably has a molecular weight of at least about 150 grams per mole. In one embodiment, the molecular weight of such compound is at least 300 grams per mole. In another embodiment, the molecular weight of such compound is 400 grams per mole.

The compound of this invention preferably has a positive magnetic susceptibility of at least 1,000×10<sup>−6 </sup>centimeter-gram-seconds (cgs). As is known to those skilled in the art, magnetic susceptibility is the ratio of the magnetization of a material to the magnetic filed strength. Reference may be had, e.g., to U.S. Pat. Nos. 3,614,618 (magnetic susceptibility tester), 3,644,823 (nulling coil apparatus for magnetic susceptibility logging), 3,657,636 (thermally stable coil assembly for magnetic susceptibility logging), 3,665,297 (apparatus for determining magnetic susceptibility in a controlled chemical and thermal environment), 3,758,847 (method and system with voltage cancellation for measuring the magnetic susceptibility of a subsurface earth formation), 3,758,848 (magnetic susceptibility well logging system), 3,879,658 (apparatus for measuring magnetic susceptibility), 3,890,563 (magnetic susceptibility logging apparatus for distinguishing ferromagnetic materials), 3,980,076 (method for measuring externally of the human body magnetic susceptibility changes), 4,079,730 (apparatus for measuring externally of the human body magnetic susceptibility changes), 4,277,750 (induction probe for the measurement of magnetic susceptibility), 4,359,399 (taggands with induced magnetic susceptibility), 4,507,613 (method for identifying non-magnetic minerals in earth formations utilizing magnetic susceptibility measurements), 4,662,359 (use of magnetic susceptibility probes in the treatment of cancer), 4,701,712 (thermoregulated magnetic susceptibility sensor assembly), 5,233,992 (MRI method for high liver iron measurement using magnetic susceptibility induced field distortions), 6,208,884 (noninvasive room temperature instrument to measure magnetic susceptibility variations in body tissue), 6,321,105 (contrast agents with high magnetic susceptibility), 6,477,398 (resonant magnetic susceptibility imaging), and the like. The entire disclosure of each of these United States patent applications is hereby incorporated by reference into this specification.

In one embodiment, the compound of this invention has a positive magnetic susceptibility of at least 5,000×10<sup>−6 </sup>cgs. In another embodiment, such compound has a positive magnetic susceptibility of at least 10,000×10<sup>−6 </sup>cgs.

The compound of this invention is preferably comprised of at least 7 carbon atoms and, more preferably, at least about 10 carbon atoms. In another embodiment, such compound is comprised of at least 13 carbon atoms and at least one aromatic ring structure containing at least one carbon-to-double double bond. In another embodiment, such compound is comprised of at least 17 carbon atoms.

In one preferred atom, the inorganic atom is radioactive. As is known to those skilled in the art, radioactivity is a phenomenon characterized by spontaneous disintegration of atomic nuclei with emission of corpuscular or electromagnetic radiation.

One preferred class of atoms is the class of radioactive nuclides. As is known to those skilled in the art, radioactive nuclides are atoms disintegrate by emission of corpuscular or electromagnetic radiatons. The rays most commonly emitted are alpha or beta gamma rays. See, e.g., page F-109 of the aforementioned “CRC Handbook of Chemistry and Physics.”

Radioactive nuclides are well known and are described, e.g., in U.S. Pat. Nos. 4,355,179 (radioactive nuclide labeled propiophenone compounds), 4,625,118 (device for the elution and metering of a radioactive nuclide), 5,672,876 (method and apparatus for measuring distribution of radioactive nuclide in a subject), and 6,607,710 (bisphosphonic acid derivative and compound thereof labeled with radioactive nuclide.). The entire disclosure of each of these United States patents is hereby incorporated by reference into this specification.

The compound of this invention preferably has a magnetic moment of at least about 0.5 Bohr magnetrons per molecule and, more preferably, at least about 1.0 Bohr magnetrons per molecule. In one embodiment, the compound has a magnetic moment of at least about 2 Bohr magnetrons per molecule.

As is known to those skilled in the art, a Bohr magnetron is the amount he/4(pi)mc, wherein he is Plank's constant, e and m are the charge and mass of the electron, c is the speed of light, and pi is equal to about 3.14567. Reference may be had, e.g., to U.S. Pat. Nos. 4,687,331, 4,832,877, 4,849,107, 5,040,373 (“(One Bohr magnetron is equal to 9.273×10<sup>−24 </sup>Joules/Tesla”), 5,169,944, 5,323,227 (“duo is a constant known as the Bohr magnetron at 9.274×10−21 erg/Gauss”), 5,352,979 6,383,597, 6,725,668, 6,739,137 (“One Bohr magnetron μB is equal to 9.273×10−24 Joules/Tesla”), and the like. The entire disclosure of each of these United States patents is hereby incorporated by reference into this specification.

Other Magnetic Compounds

In another embodiment of this invention, other compounds which are not necessarily anti-mitotic are made magnetic by a process comparable to the process described in this specification for making taxanes magnetic.

In this embodiment, it is preferred to make “magnetic derivatives” of drugs and therapeutic agents. These derivative compounds each preferably have a molecular weight of at least 150 grams per mole, a positive magnetic susceptibility of at least 1,000×10<sup>−6 </sup>cgs, and a magnetic moment of at least 0.5 bohr magnetrons, wherein said compound is comprised of at least 7 carbon atoms and at least one inorganic atom with a positive magnetic susceptibility of at least 200×10<sup>−6 </sup>cgs.

Some of the preferred “precursors” used to make these “derivative compounds” are described in the remainder of this section of the specification.

The precursor materials may be either proteinaceous or non-proteinaceous drugs, as they terms are defined in U.S. Pat. No. 5,194,581, the entire disclosure of which is hereby incorporated by reference into this specification. U.S. Pat. No. 5,194,581 discloses “The drugs with which can be incorporated in the compositions of the invention include non-proteinaceous as well as proteinaceous drugs. The term “non-proteinaceous drugs” encompasses compounds which are classically referred to as drugs such as, for example, mitomycin C, daunorubicin, vinblastine, AZT, and hormones. Similar substances are within the skill of the art. The proteinaceous drugs which can be incorporated in the compositions of the invention include immunomodulators and other biological response modifiers. The term “biological response modifiers” is meant to encompass substances which are involved in modifying the immune response in such manner as to enhance the particular desired therapeutic effect, for example, the destruction of the tumor cells. Examples of immune response modifiers include such compounds as lymphokines. Examples of lymphokines include tumor necrosis factor, the interleukins, lymphotoxin, macrophage activating factor, migration inhibition factor, colony stimulating factor and the interferons. Interferons which can be incorporated into the compositions of the invention include alpha-interferon, beta-interferon, and gamma-interferon and their subtypes. In addition, peptide or polysaccharide fragments derived from these proteinaceous drugs, or independently, can also be incorporated. Also, encompassed by the term “biological response modifiers” are substances generally referred to as vaccines wherein a foreign substance, usually a pathogenic organism or some fraction thereof, is used to modify the host immune response with respect to the pathogen to which the vaccine relates. Those of skill in the art will know, or can readily ascertain, other substances which can act as proteinaceous drugs.”

The precursor may be a lectin, as is disclosed in U.S. Pat. No. 5,176,907, the entire disclosure of which is hereby incorporated by reference into this specification. This United States patent discloses “Lectins are proteins, usually isolated from plant material, which bind to specific sugar moieties. Many lectins are also able to agglutinate cells and stimulate lymphocytes. Other therapeutic agents which can be used therapeutically with the biodegradable compositions of the invention are known, or can be easily ascertained, by those of ordinary skill in the art.”

The precursor material may be an amorphous water-soluble pharmaceutical agent, as is disclosed in U.S. Pat. No. 6,117,455, the entire disclosure of which is hereby incorporated by reference into this specification. As is disclosed in the abstract of this patent, there is provided “A sustained-release microcapsule contains an amorphous water-soluble pharmaceutical agent having a particle size of from 1 nm-10 μm and a polymer. The microcapsule is produced by dispersing, in an aqueous phase, a dispersion of from 0.001-90% (w/w) of an amorphous water-soluble pharmaceutical agent in a solution of a polymer having a wt. avg. molecular weight of 2,000-800,000 in an organic solvent to prepare an s/o/w emulsion and subjecting the emulsion to in-water drying.”

In one embodiment, and referring to U.S. Pat. No. 5,420,105 (the entire disclosure of which is hereby incorporated by reference into this specification), the precursor material is selected from the group consisting of an anti-cancer anthracycline antibiotic, cis-platinum, methotrexate, vinblastine, mitoxanthrone ARA-C, 6-mercaptopurine, 6-mercaptoguanosine, mytomycin C and a steroid.

By way of further illustration, the precursor material is selected from the group consisting of antithrombogenic agents, antiplatelet agents, prostaglandins, thrombolytic drugs, antiproliferative drugs, antirejection drugs, antimicrobial drugs, growth factors, and anticalcifying agents.

By way of yet further illustration, the precursor material may, e.g., be any one or more of the therapeutic agents disclosed in column 5 of U.S. Pat. No. 5,464,650. Thus, and referring to such column 5, “The therapeutic substance used in the present invention could be virtually any therapeutic substance which possesses desirable therapeutic characteristics for application to a blood vessel. This can include both solid substances and liquid substances. For example, glucocorticoids (e.g. dexamethasone, betamethasone), heparin, hirudin, tocopherol, angiopeptin, aspirin, ACE inhibitors, growth factors, oligonucleotides, and, more generally, antiplatelet agents, anticoagulant agents, antimitotic agents, antioxidants, antimetabolite agents, and anti-inflammatory agents could be used. Antiplatelet agents can include drugs such as aspirin and dipyridamole. Aspirin is classified as an analgesic, antipyretic, anti-inflammatory and antiplatelet drug. Dypridimole is a drug similar to aspirin in that it has anti-platelet characteristics. Dypridimole is also classified as a coronary vasodilator. Anticoagulant agents can include drugs such as heparin, coumadin, protamine, hirudin and tick anticoagulant protein. Antimitotic agents and antimetabolite agents can include drugs such as methotrexate, azathioprine, vincristine, vinblastine, fluorouracil, adriamycin and mutamycin.”

The precurors material may be one or more of the drugs disclosed in U.S. Pat. No. 5,599,352, the entire disclosure of which is hereby incorporated by reference into this specification. As is disclosed in this patent, “Examples of drugs that are thought to be useful in the treatment of restenosis are disclosed in published international patent application WO 91/12779 “Intraluminal Drug Eluting Prosthesis” which is incorporated herein by reference. Therefore, useful drugs for treatment of restenosis and drugs that can be incorporated in the fibrin and used in the present invention can include drugs such as anticoagulant drugs, antiplatelet drugs, antimetabolite drugs, anti-inflammatory drugs and antimitotic drugs. Further, other vasoreactive agents such as nitric oxide releasing agents could also be used . . . By this method, drugs such as glucocorticoids (e.g. dexamethasone, betamethasone), heparin, hirudin, tocopherol, angiopeptin, aspirin, ACE inhibitors, growth factors, oligonucleotides, and, more generally, antiplatelet agents, anticoagulant agents, antimitotic agents, antioxidants, antimetabolite agents, and anti-inflammatory agents can be applied to a stent . . . ”

By way of yet further illustration, and referring to U.S. Pat. No. 5,900,433 (the entire disclosure of which is hereby incorporated by reference into this specification), the precursor material may be a congener of an endothelium-derived bioactive composition of matter. This congener is discussed in column 7 of the patent, wherein it is disclosed that “We have discovered that administration of a congener of an endothelium-derived bioactive agent, more particularly a nitrovasodilator, representatively the nitric oxide donor agent sodium nitroprusside, to an extravascular treatment site, at a therapeutically effective dosage rate, is effective for abolishing CFR's while reducing or avoiding systemic effects such as supression of platelet function and bleeding . . . congeners of an endothelium-derived bioactive agent include prostacyclin, prostaglandin E1, and a nitrovasodilator agent. Nitrovasodilater agents include nitric oxide and nitric oxide donor agents, including L-arginine, sodium nitroprusside and nitroglycycerine.”

By way of yet further illustration, the precursor material may be heparin. As is disclosed in U.S. Pat. No. 6,120,536 (the entire disclosure of which is hereby incorporated by reference into this specification), “While heparin is preferred as the incorporated active material, agents possibly suitable for incorporation include antithrobotics, anticoagulants, antibiotics, antiplatelet agents, thorombolytics, antiproliferatives, steroidal and non-steroidal antinflammatories, agents that inhibit hyperplasia and in particular restenosis, smooth muscle cell inhibitors, growth factors, growth factor inhibitors, cell adhesion inhibitors, cell adhesion promoters and drugs that may enhance the formation of healthy neointimal tissue, including endothelial cell regeneration.”

In one preferred embodiment, the magnetic properties of the anti-mitotic compound of this invention are used in order to preferentially deliver such compound to a specified site. In another embodiment, the magnetic properties of the compounds and compositions of this invention which are not necessarily anti-mitotic but have the desired magnetic properties also may be used to deliver such compounds and/or compositions to a desired site.

Thus, by way of illustration, one may guide delivery of the compound of this invention with conventional magnetic focusing means. In one aspect of this embodiment, a magnetic field of a specified strength is focused onto a desired therapeutic site, such as a tumor to be treated, whereby the compound is selectively drawn to the therapeutic site and binds with tubulin moleuces at the site. In one embodiment, the focused magnetic field has a field strength of at least about 6 Tesla in order to cause microtubules to move linearly. The magnetic field may, e.g., be focused for a period of at least about 30 minutes following the administration of the compound of this invention.

One may use any of the conventional magnetic field generators known to those skilled in the art to produce such a magnetic field. Thus, e.g., one may use one or more of the magnetic field generators disclosed in U.S. Pat. Nos. 6,503,364, 6,377,149 (magnetic field generator for magnetron plasma generation), 6,353,375 (magnetostatic wave device), 6,340,888 (magnetic field generator for MRI), 6,336,989, 6,335,617 (device for calibrating a magnetic field generator), 6,313,632, 6,297,634, 6,275,128, 6,246,066 (magnetic field generator and charged particle beam irradiator), 6,114,929 (magnetostatic wave device), 6,099,459 (magnetic field generating device and method of generating and applying a magnetic field), 5,795,212, 6,106,380 (deterministic magnetorheological finishing), 5,839,944 (apparatus for deterministic magnetorheological finishing), 5,971,835 (system for abrasive jet shaping and polishing of a surface using a magnetorheological fluid), 5,951,369, 6,506,102 (system for magnetorheological finishing of substrates), 6,267,651, 6,309,285 (magnetic wiper), 5,929,732 and 6,488,615 I(which describe devices and methods for creating a high intensity magnetic field for magnetically guiding a anti-mitotic compound to a predetermined site within a biological organism), and the like. The entire disclosure of each of these United States patents is hereby incorporated by reference into this specification.

The Use of Externally Applied Energy to Affect an Implanted Medical Device

The prior art discloses many devices in which an externally applied electromagnetic field (i.e., a field originating outside of a biological organism, such as a human body) is generated in order to influence one or more implantable devices disposed within the biological organism; these may be used in conjunction with anti-mitotic compound of this invention. Some of these devices are described below.

U.S. Pat. No. 3,337,776 describes a device for producing controllable low frequency magnetic fields; the entire disclosure of this patent is hereby incorporated by reference into this specification. Thus, e.g., claim 1 of this patent describes a biomedical apparatus for the treatment of a subject with controllable low frequency magnetic fields, comprising solenoid means for creating the magnetic field. These low-frequency magnetic fields may be used to affect the anti-mitotic compounds of this invention, and/or tubulin and/or microtubules and/or other moieties.

U.S. Pat. No. 3,890,953 also discloses an apparatus for promoting the growth of bone and other body tissues by the application of a low frequency alternating magnetic field; the entire disclosure of this United States patent is hereby incorporated by reference into this specification. This patent claims “In an electrical apparatus for promoting the growth of bone and other body tissues by the application thereto of a low frequency alternating magnetic field, such apparatus having current generating means and field applicator means, the improvement wherein the applicator means comprises a flat solenoid coil having an axis about which the coil is wound and composed of a plurality of parallel and flexible windings, each said winding having two adjacent elongate portions and two 180° coil bends joining said elongate portions together, said coil being flexible in the coil plane in the region of said elongate portion for being bent into a U-shape, said coil being bent into such U-shape about an axis parallel to the coil axis and adapted for connection to a source of low frequency alternating current.” These low-frequency magnetic fields may be used to affect the anti-mitotic compounds of this invention, and/or tubulin and/or microtubules and/or other moieties.

The device of U.S. Pat. No. 3,890,953 is described, in part, at lines 52 et seq. of column 2, wherein it is disclosed that: “.The apparatus shown diagrammatically in FIG. 1 comprises a AC generator 10, which supplies low frequency AC at the output terminals 12. The frequency of the AC lies below 150 Hz, for instance between 1 and 50 or 65 Hz. It has been found particularly favorable to use a frequency range between 5 or 10 and 30 Hz, for example 25 Hz. The half cycles of the alternating current should have comparatively gently sloping leading and trailing flanks (rise and fall times of the half cycles being for example in the order of magnitude of a quarter to an eighth of the length of a cycle); the AC can thus be a sinusoidal current with a low non-linear distortion, for example less than 20 percent, or preferably less than 10 percent, or a triangular wave current.”

U.S. Pat. No. 4,095,588 discloses a “vascular cleansing device” adapted to “ . . . effect motion of the red corpuscles in the blood stream of a vascular system . . . whereby these red cells may cleanse the vascular system by scrubbing the walls thereof . . . ;” the entire disclosure of this United States patent is hereby incorporated by reference into this specification. This patent claims (in claim 3) “A means to propel a red corpuscle in a vibratory and rotary fashion, said means comprising an electronic circuit and magnetic means including: a source of electrical energy; a variable oscillator connected to said source; a binary counter means connected to said oscillator to produce sequential outputs; a plurality of deflection amplifier means connected to be operable by the outputs of said binary counter means in a sequential manner, said amplifier means thereby controlling electrical energy from said source; a plurality of separate coils connected in separate pairs about an axis in series between said deflection amplifier means and said source so as to be sequentially operated in creating an electromagnetic field from one coil to the other and back again and thence to adjacent separate coils for rotation of the electromagnetic field from one pair of coils to another; and a table within the space encircled by said plurality of coils, said table being located so as to place a person along the axis such that the red corpuscles of the person's vascular system are within the electromagnetic field between the coils creating same.” The energy used to affect such red blood corpuscles may also be used affect the anti-mitotic compounds of this invention, and/or tubulin and/or microtubules and/or other moieties.

U.S. Pat. No. 4,323,075 discloses an implantable defibrillator with a rechargeable power supply; the entire disclosure of this patent is hereby incorporated by reference into this specification. Claim 1 of this patent describes “A fully implantable power supply for use in a fully implantable defibrillator having an implantable housing, a fibrillation detector for detecting fibrillation of the heart of a recipient, an energy storage and discharge device for storing and releasing defibrillation energy into the heart of the recipient and an inverter for charging the energy storage and discharge device in response to detection of fibrillation by the fibrillation detector, the inverter requiring a first level of power to be operational and the fibrillation detector requiring a second level of power different from said first level of power to be operational, said power supply comprising: implantable battery means positioned within said implantable housing, said battery means including a plurality of batteries arranged in series, each of said batteries having a pair of output terminals, each of said batteries producing a distinctly multilevel voltage across its pair of output terminals, said voltage being at a first level when the battery is fully charged and dropping to a second level at some point during the discharge of the battery; and implantable circuit means positioned within said implantable housing, said circuit means for creating a first conductive path betwen said serially-connected batteries and said fibrillation detector to provide said fibrillation detector with said second level of power, and for creating a second conductive path between said inverter and said battery means by placing only the batteries operating at said first level voltage in said second conductive path, and excluding the remaining batteries from said second conductive path to provide said inverter with said first level of power.” The power supply of this patent may be used to power, e.g., one or more magnetic focusing devices.

U.S. Pat. No. 4,340,038 discloses an implanted medical system comprised of magnetic field pick-up means for converting magnetic energy to electrical energy; the entire disclosure of this patent is hereby incorporated by reference into this specification. One may use the electrical energy produced by such pick-up means to affect the anti-mitotic compounds of this invention, and/or tubulin and/or microtubules and/or other moieties. Such energy may also be used to power an implanted magnetic focusing device.

In column 1 of U.S. Pat. No. 4,340,038, at lines 12 et seq., it is disclosed that “Many types of implantable devices incorporate a self-contained transducer for converting magnetic energy from an externally-located magnetic field generator to energy usable by the implanted device. In such a system having an implanted device and an externally-located magnetic field generator for powering the device, sizing and design of the power transfer system is important. In order to properly design the power transfer system while at the same time avoiding overdesign, the distance from the implanted device to the magnetic field generator must be known. However for some types of implanted devices the depth of the implanted device in a recipient's body is variable, and is not known until the time of implantation by a surgeon. One example of such a device is an intracranial pressure monitoring device (ICPM) wherein skull thickness varies considerably between recipients and the device must be located so that it protrudes slightly below the inner surface of the skull and contacts the dura, thereby resulting in a variable distance between the top of the implanted device containing a pick-up coil or transducer and the outer surface of the skull. One conventional technique for accommodating an unknown distance between the magnetic field generator and the implanted device includes increasing the transmission power of the external magnetic field generator. However this increased power can result in heating of the implanted device, the excess heat being potentially hazardous to the recipient. A further technique has been to increase the diameter of the pick-up coil in the implanted device. However, physical size constraints imposed on many implanted devices such as the ICPM are critical; and increasing the diameter of the pick-up coil is undesirable in that it increases the size of the orifice which must be formed in the recipient's skull. The concentrator of the present invention solves the above problems by concentrating magnetic lines of flux from the magnetic generator at the implanted pick-up coil, the concentrator being adapted to accommodate distance variations between the implanted device and the magnetic field generator.’

Claim 1 of U.S. Pat. No. 4,340,038 describes “In a system including an implanted device having a magnetic field pick-up means for converting magnetic energy to electrical energy for energizing said implanted device, and an external magnetic field generator located so that magnetic lines of flux generated thereby intersect said pick-up means, a means for concentrating a portion of said magnetic lines of flux at said pick-up means comprising a metallic slug located between said generator and said pick-up means, thereby concentrating said magnetic lines of flux at said pick-up means. “Claim 5 of this patent further describes the pick-up means as comprising “ . . . a magnetic pick-up coil and said slug is formed in the shape of a truncated cone and oriented so that a plane defined by the smaller of said cone end surfaces is adjacent to said substantially parallel to a plane defined by said magnetic pick-up coil.” In one embodiment, such pick-up means may be located near the site to be treated (such as a tumor) and may be used to affect the tumor by, e.g., hyperthermia treatement.

U.S. Pat. No. 4,361,153 discloses an implantable telemetry system; the entire disclosure of such United States patent is hereby incorporated by reference into this specification. Such an implantable telemetry system, equipped with a multiplicity of sensors, may be used to report how These the anti-mitotic compounds of this invention, and/or tubulin and/or microtubules and/or other moieties respond to applied electromagnetic fields.

As is disclosed at column 1 of U.S. Pat. No. 4,361,153 (see lines 9 et seq.), “Externally applied oscillating magnetic fields have been used before with implanted devices. Early inductive cardiac pacers employed externally generated electromagnetic energy directly as a power source. A coil inside the implant operated as a secondary transformer winding and was interconnected with the stimulating electrodes. More recently, implanted stimulators with rechargeable (e.g., nickel cadmium) batteries have used magnetic transmission to couple energy into a secondary winding in the implant to energize a recharging circuit having suitable rectifier circuitry. Miniature reed switches have been utilized before for implant communications. They appear to have been first used to allow the patient to convert from standby or demand mode to fixed rate pacing with an external magnet. Later, with the advent of programmable stimulators, reed switches were rapidly cycled by magnetic pulse transmission to operate pulse parameter selection circuitry inside the implant. Systems analogous to conventional two-way radio frequency (RF) and optical communication system have also been proposed. The increasing versatility of implanted stimulators demands more complex programming capabilities. While various systems for transmitting data into the implant have been proposed, there is a parallel need to develop compatible telemetry systems for signalling out of the implant. However, the austere energy budget constraints imposed by long life, battery operated implants rule out conventional transmitters and analogous systems.”

The solution provided by U.S. Pat. No. 4,361,153 is “ . . . achieved by the use of a resonant impedance modulated transponder in the implant to modulate the phase of a relatively high energy reflected magnetic carrier imposed from outside of the body.” In particular, and as is described by claim 1 of this patent, there is claimed “An apparatus for communicating variable information to an external device from an electronic stimulator implanted in a living human patient, comprising an external unit including means for transmitting a carrier signal, a hermetically sealed fully implantable enclosure adapted to be implanted at a fixed location in the patient's body, means within said enclosure for generating stimulator outputs, a transponder within said enclosure including tuned resonant circuit means for resonating at the frequency of said carrier signal so as to re-radiate a signal at the frequency of said carrier signal, and means for superimposing an information signal on the reflected signal by altering the resonance of said tuned circuit means in accordance with an information signal, said superimposing means including a variable impedance load connected across said tuned circuit and means for varying the impedance of said load in accordance with an information signal, said external unit further including pickup means for receiving the reflected signal from said transponder and means for recovering the information signal superimposed thereon, said receiving means including means reponsive to said reflected signal from said transponder for producing on associated analog output signal, and said recovering means including phase shift detector means responsive to said analog output signal for producing an output signal related to the relative phase angle thereof.”

U.S. Pat. No. 4,408,607 discloses a rechargeable, implantable capacitive energy source; the entire disclosure of this patent is hereby incorporated into this specification by reference; and this source may be used to directly or indirectly supply energy to one or more of the anti-mitotic compounds of this invention, and/or tubulin and/or microtubules and/or other moieties. As is disclosed in column 1 of such patent (at lines 12 et seq.), “Medical science has advanced to the point where it is possible to implant directly within living bodies electrical devices necessary or advantageous to the welfare of individual patients. A problem with such devices is how to supply the electrical energy necessary for their continued operation. The devices are, of course, designed to require a minimum of electrical energy, so that extended operation from batteries may be possible. Lithium batteries and other primary, non-rechargeable cells may be used, but they are expensive and require replacement of surgical procedures. Nickel-cadmium and other rechargeable batteries are also available, but have limited charge-recharge characteristics, require long intervals for recharging, and release gas during the charging process.”

The solution to this problem is described, e.g., in claim 1 of the patent, which describes “An electric power supply for providing electrical energy to an electrically operated medical device comprising: capacitor means for accommodating an electric charge; first means providing a regulated source of unidirectional electrical energy; second means connecting said first means to said capacitor means for supplying charging current to said capacitor means at a first voltage which increases with charge in the capacitor means; third means deriving from said first means a comparison second voltage of constant magnitude; comparator means operative when said first voltage reaches a first value to reduce said first voltage to a second, lower value; and voltage regulator means connected to said capacitor means and medical device to limit the voltage supplied to the medical device.”

U.S. Pat. No. 4,416,283 discloses a implantable shunted coil telemetry transponder employed as a magnetic pulse transducer for receiving externally transmitted data; the entire disclosure of this United States patent is hereby incorporated by reference into this specification. This transponder may be used in a manner similar to that of the aforementioned telemetry system.

In particular, a programming system for a biomedical implant is described in claim 1 of U.S. Pat. No. 4,416,283. Such claim 1 discloses “In a programming system for a biomedical implant of the type wherein an external programmer produces a series of magnetic impulses which are received and transduced to form a corresponding electrical pulse input to programmable parameter data registers inside the implant, wherein the improvement comprises external programming pulse receiving and transducing circuitry in the implant including a tuned coil, means responsive to pairs of successive voltage spikes of opposite polarity magnetically induced across said tuned coil by said magnetic impulses for forming corresponding binary pulses duplicating said externally generated magnetic impulses giving rise to said spikes, and means for outputting said binary pulses to said data registers to accomplish programming of the implant.”

U.S. Pat. No. 4,871,351 discloses an implantable pump infusion system; the entire disclosure of this United States patent is hereby incorporated by reference into this specification. These implantable pumps are discussed in column 1 of the patent, wherein it is disclosed that: “Certain human disorders, such as diabetes, require the injection into the body of prescribed amounts of medication at prescribed times or in response to particular conditions or events. Various kinds of infusion pumps have been propounded for infusing drugs or other chemicals or solutions into the body at continuous rates or measured dosages. Examples of such known infusion pumps and dispensing devices are found in U.S. Pat. Nos. 3,731,861; 3,692,027; 3,923,060; 4,003,379; 3,951,147; 4,193,397; 4,221,219 and 4,258,711. Some of the known pumps are external and inject the drugs or other medication into the body via a catheter, but the preferred pumps are those which are fully implantable in the human body.” One may use the implantable pumps of this patent to delivery the anti-mitotic compound of this invention to a specified site and, thereafter, to “finely focus” such delivery by means of magnetic focusing means.

U.S. Pat. No. 4,871,351 also discloses that: “Implantable pumps have been used in infusion systems such as those disclosed in U.S. Pat. Nos. 4,077,405; 4,282,872; 4,270,532; 4,360,019 and 4,373,527. Such infusion systems are of the open loop type. That is, the systems are pre-programmed to deliver a desired rate of infusion. The rate of infusion may be programmed to vary with time and the particular patient. A major disadvantage of such open loop systems is that they are not responsive to the current condition of the patient, i.e. they do not have feedback information. Thus, an infusion system of the open loop type may continue dispensing medication according to its pre-programmed rate or profile when, in fact, it may not be needed.”

U.S. Pat. No. 4,871,351 also discloses that: “There are known closed loop infusion systems which are designed to control a particular condition of the body, e.g. the blood glucose concentration. Such systems use feedback control continuously, i.e. the patient's blood is withdrawn via an intravenous catheter and analysed continuously and a computer output signal is derived from the actual blood glucose concentration to drive a pump which infuses insulin at a rate corresponding to the signal. The known closed loop systems suffer from several disadvantages. First, since they monitor the blood glucose concentration continuously they are complex and relatively bulky systems external to the patient, and restrict the movement of the patient. Such systems are suitable only for hospital bedside applications for short periods of time and require highly trained operating staff. Further, some of the known closed loop systems do not allow for manually input overriding commands. Examples of closed loop systems are found in U.S. Pat. Nos. 4,055,175; 4,151,845 and 4,245,634.”

U.S. Pat. No. 4,871,351 also discloses that “An implanted closed loop system with some degree of external control is disclosed in U.S. Pat. No. 4,146,029. In that system, a sensor (either implanted or external) is arranged on the body to sense some kind of physiological, chemical, electrical or other condition at a particular site and produced data which corresponds to the sensed condition at the sensed site. This data is fed directly to an implanted microprocessor controlled medication dispensing device. A predetermined amount of medication is dispensed in response to the sensed condition according to a pre-programmed algorithm in the microprocessor control unit. An extra-corporeal coding pulse transmitter is provided for selecting between different algorithms in the microprocessor control unit. The system of U.S. Pat. No. 4,146,029 is suitable for use in treating only certain ailments such as cardiac conditions. It is unsuitable as a blood glucose control system for example, since (i) it is not practicable to measure the blood glucose concentration continuously with an implanted sensor and (ii) the known system is incapable of dispensing discrete doses of insulin in response to certain events, such as meals and exercise. Furthermore, there are several disadvantages to internal sensors; namely, due to drift, lack of regular calibration and limited life, internal sensors do not have high long-term reliability. If an external sensor is used with the system of U.S. Pat. No. 4,146,029, the output of the sensor must be fed through the patient's skin to the implanted mechanism. There are inherent disadvantages to such a system, namely the high risk of infection. Since the algorithms which control the rate of infusion are programmed into the implanted unit, it is not possible to upgrade these algorithms without surgery. The extra-corporeal controller merely selects a particular one of several medication programs but cannot actually alter a program.”

U.S. Pat. No. 4,871,351 also discloses that “It is an object of the present invention to overcome, or substantially ameliorate the above described disadvantages of the prior art by providing an implantable open loop medication infusion system with a feedback control option.”

The solution to this problem is set forth in claim 1 of U.S. Pat. No. 4,871,351, which describes: “A medical infusion system intermittently switchable at selected times between an open loop system without feedback and a closed loop system with feedback, said system comprising an implantable unit including means for controllably dispensing medication into a body, an external controller, and an extra-corporeal sensor; wherein said implantable unit comprises an implantable transceiver means for communicating with a similar external transceiver means in said external controller to provide a telemetry link between said controller and said implantable unit, a first reservoir means for holding medication liquid, a liquid dispensing device, a pump connected between said reservoir means and said liquid dispensing device, and a first electronic control circuit means connected to said implantable transceiver means and to said pump to operate said pump; wherein said external controller comprises a second electronic control circuit means connected with said external transceiver means, a transducer means for reading said sensor, said transducer means having an output connected to said second electronic control circuit means, and a manually operable electric input device connected to said second electronic control circuit means; wherein said pump is operable by said first electronic control circuit means to pump said medication liquid from said first reservoir means to said liquid-dispensing deive at a first predetermined rate independent of the output of said extra-corporeal sensor, and wherein said input device or said transducer means include means which selectively operable at intermittent times to respectively convey commands or output of said transducer representing the reading of said sensor to said second control circuit to instruct said first control circuit via said telemetry link to modify the operation of said pump.”

U.S. Pat. No. 4,941,461 describes an electrically actuated inflatable penile erecton device comprised of an implantable induction coil and an implantable pump; the entire disclosure of this United States patent is hereby incorporated by reference into this specification. The device of this patent is described, e.g., in claim 1 of the patent, which discloses “An apparatus for achieving a penile erection in a human male, comprising: at least one elastomer cylinder having a root chamber and a pendulous chamber, said elastomer cylinder adapted to be placed in the corpus carvenosum of the penis; an external magnetic field generator which can be placed over some section of the penis which generates an alternating magnetic field; an induction coil contained within said elastomer cylinder which produces an alternating electric current when in the proximity of said alternating magnetic filed which is produced by said external magnetic field generator; and a fluid pumping means located within said elastomer cylinder, said pumping means being operated by the electrical power generated in said induction coil to pump fluid from said root chamber to said pendulous chamber in order to stiffen said elastomer cylinder for causing the erect state of the penis.”

U.S. Pat. No. 5,487,760 discloses an implantable signal transceiver disposed in an artificial heart valve; this transceiver may be used in the process of this invention in accordance with the aforementioned telemetry device; and the entire disclosure of this United States patent is hereby incorporated by reference into this specification. Claim 1 of this patent describes: “In combination, an artificial heart valve of the type having a tubular body member, defining a lumen and pivotally supporting at least one occluder, said body member having a sewing cuff covering an exterior surface of said body member; and an electronic sensor module disposed between said sewing cuff and said exterior surface, wherein said sensor module incorporates a sensor element for detecting movement of said at least one occluder between an open and a closed disposition relative to said lumen and wherein said sensor module further includes a signal transceiver coupled to said sensor element, and means for energizing said signal transceiver, and wherein said sensor module includes means for encapsulating said sensor element, signal transceiver and energizing means in a moisture-impervious container.” As will be apparent to those skilled in the art, the sensor/transceiver combination may advantageously be used in conjunction with the anti-mitotic compound of this invention, and/or microtubules.

U.S. Pat. No. 5,702,430 discloses an implantable power supply; the entire disclosure of such patent is hereby incorporated by reference into this specification. This implantable power supply may be used to supply power to either the compound of this invention, the treatment site, and/or one or more other devices from which a specified energy output is desired.

Claim 1 of U.S. Pat. No. 5,702,430 describes: “A surgically implantable power supply comprising battery means for providing a source of power, charging means for charging the battery means, enclosure means isolating the battery means from the human body, gas holding means within the enclosure means for holding gas generated by the battery means during charging, seal means in the enclosure means arranged to rapture when the internal gas pressure exceeds a certain value and inflatable gas container means outside the enclosure means to receive gas from within the enclosure means when the seal means has been ruptured.”

Columns 1 through 5 of U.S. Pat. No. 5,702,430 presents an excellent discussion of “prior art” implantable pump assemblies that may be used, e.g., to deliver the anti-mitotic compound of this invention. As is disclosed in such portion of United States patent 5,702,430, “The most widely tested and commonly used implantable blood pumps employ variable forms of flexible sacks (also spelled sacs) or diaphragms which are squeezed and released in a cyclical manner to cause pulsatile ejection of blood. Such pumps are discussed in books or articles such as Hogness and Antwerp 1991, DeVries et al 1984, and Farrar et al 1988, and in U.S. Pat. No. 4,994,078 (Jarvik 1991), 4,704,120 (Slonina 1987), 4,936,758 (Coble 1990), and 4,969,864 (Schwarzmann et al 1990). Sack or diaphragm pumps are subject to fatigue failure of compliant elements and as such are mechanically and functionally quite different from the pump which is the subject of the present invention.”

U.S. Pat. No. 5,702,430 also discloses that “An entirely different class of implantable blood pumps uses rotary pumping mechanisms. Most rotary pumps can be classified into two categories: centrifugal pumps and axial pumps. Centrifugal pumps, which include pumps marketed by Sarns (a subsidiary of the 3M Company) and Biomedicus (a subsidiary of Medtronic, Eden Prairie, Minn.), direct blood into a chamber, against a spinning interior wall (which is a smooth disk in the Medtronic pump). A flow channel is provided so that the centrifugal force exerted on the blood generates flow.”

U.S. Pat. No. 5,702,430 also discloses that “By contrast, axial pumps provide blood flow along a cylindrical axis, which is in a straight (or nearly straight) line with the direction of the inflow and outflow. Depending on the pumping mechanism used inside an axial pump, this can in some cases reduce the shearing effects of the rapid acceleration and deceleration forces generated in centrifugal pumps. However, the mechanisms used by axial pumps can inflict other types of stress and damage on blood cells.”

U.S. Pat. No. 5,702,430 also discloses that “Some types of axial rotary pumps use impeller blades mounted on a center axle, which is mounted inside a tubular conduit. As the blade assembly spins, it functions like a fan, or an outboard motor propeller. As used herein, “impeller” refers to angled vanes (also called blades) which are constrained inside a flow conduit; an impeller imparts force to a fluid that flows through the conduit which encloses the impeller. By contrast, “propeller” usually refers to non-enclosed devices, which typically are used to propel vehicles such as boats or airplanes.” “Another type of axial blood pump, called the “Haemopump” (sold by Nimbus) uses a screw-type impeller with a classic screw (also called an Archimedes screw; also called a helifoil, due to its helical shape and thin cross-section). Instead of using several relatively small vanes, the Haemopump screw-type impeller contains a single elongated helix, comparable to an auger used for drilling or digging holes. In screw-type axial pumps, the screw spins at very high speed (up to about 10,000 rpm). The entire Haemopump unit is usually less than a centimeter in diameter. The pump can be passed through a peripheral artery into the aorta, through the aortic valve, and into the left ventricle. It is powered by an external motor and drive unit.”

U.S. Pat. No. 5,702,430 also discloses that “Centrifugal or axial pumps are commonly used in three situations: (1) for brief support during cardiopulmonary operations, (2) for short-term support while awaiting recovery of the heart from surgery, or (3) as a bridge to keep a patient alive while awaiting heart transplantation. However, rotary pumps generally are not well tolerated for any prolonged period. Patients who must rely on these units for a substantial length of time often suffer from strokes, renal (kidney) failure, and other organ dysfunction. This is due to the fact that rotary devices, which must operate at relatively high speeds, may impose unacceptably high levels of turbulent and laminar shear forces on blood cells. These forces can damage or lyse (break apart) red blood cells. A low blood count (anemia) may result, and the disgorged contents of lysed blood cells (which include large quantities of hemoglobin) can cause renal failure and lead to platelet activation that can cause embolisms and stroke.”

“One of the most important problems in axial rotary pumps in the prior art involves the gaps that exist between the outer edges of the blades, and the walls of the flow conduit. These gaps are the site of severe turbulence and shear stresses, due to two factors. Since implantable axial pumps operate at very high speed, the outer edges of the blades move extremely fast and generate high levels of shear and turbulence. In addition, the gap between the blades and the wall is usually kept as small as possible to increase pumping efficiency and to reduce the number of cells that become entrained in the gap area. This can lead to high-speed compression of blood cells as they are caught in a narrow gap between the stationary interior wall of the conduit and the rapidly moving tips or edges of the blades.”

U.S. Pat. No. 5,702,430 also discloses that “An important factor that needs to be considered in the design and use of implantable blood pumps is “residual cardiac function,” which is present in the overwhelming majority of patients who would be candidates for mechanical circulatory assistance. The patient's heart is still present and still beating, even though, in patients who need mechanical pumping assistance, its output is not adequate for the patient's needs. In many patients, residual cardiac functioning often approaches the level of adequacy required to support the body, as evidenced by the fact that the patient is still alive when implantation of an artificial pump must be considered and decided. If cardiac function drops to a level of severe inadequacy, death quickly becomes imminent, and the need for immediate intervention to avert death becomes acute.’”

U.S. Pat. No. 5,702,430 also discloses that “Most conventional ventricular assist devices are designed to assume complete circulatory responsibilities for the ventricle they are “assisting. As such, there is no need, nor presumably any advantage, for the device to interact in harmony with the assisted ventricle. Typically, these devices utilize a “fill-to-empty” mode that, for the most part, results in emptying of the device in random association with native heart contraction. This type of interaction between the device and assisted ventricle ignores the fact that the overwhelming majority of patients who would be candidates for mechanical assistance have at least some significant residual cardiac function.”

U.S. Pat. No. 5,702,430 also discloses that “It is preferable to allow the natural heart, no matter how badly damaged or diseased it may be, to continue contributing to the required cardiac output whenever possible so that ventricular hemodynamics are disturbed as little as possible. This points away from the use of total cardiac replacements and suggests the use of “assist” devices whenever possible. However, the use of assist devices also poses a very difficult problem: in patients suffering from severe heart disease, temporary or intermittent crises often require artificial pumps to provide “bridging” support which is sufficient to entirely replace ventricular pumping capacity for limited periods of time, such as in the hours or days following a heart attack or cardiac arrest, or during periods of severe tachycardia or fibrillation.”

U.S. Pat. No. 5,702,430 also discloses that “Accordingly, an important goal during development of the described method of pump implantation and use and of the surgically implantable reciprocating pump was to design a method and a device which could cover a wide spectrum of requirements by providing two different and distinct functions. First, an ideal cardiac pumping device should be able to provide “total” or “complete” pumping support which can keep the patient alive for brief or even prolonged periods, if the patient's heart suffers from a period of total failure or severe inadequacy. Second, in addition to being able to provide total pumping support for the body during brief periods, the pump should also be able to provide a limited “assist” function. It should be able to interact with a beating heart in a cooperative manner, with minimal disruption of the blood flow generated by the natural heartbeat. If a ventricle is still functional and able to contribute to cardiac output, as is the case in the overwhelming majority of clinical applications, then the pump will assist or augment the residual cardiac output. This allows it to take advantage of the natural, non-hemolytic pumping action of the heart to the fullest extent possible; it minimizes red blood cell lysis, it reduces mechanical stress on the pump, and it allows longer pump life and longer battery life.” “Several types of surgically implantable blood pumps containing a piston-like member have been developed to provide a mechanical device for augmenting or even totally replacing the blood pumping action of a damaged or diseased mammalian heart.” “U.S. Pat. No. 3,842,440 to Karlson discloses an implantable linear motor prosthetic heart and control system containing a pump having a piston-like member which is reciprocal within a magnetic field. The piston-like member includes a compressible chamber in the prosthetic heart which communicates with the vein or aorta.”

U.S. Pat. No. 5,702,430 also discloses that “U.S. Pat. Nos. 3,911,897 and 3,911,898 to Leachman, Jr. disclose heart assist devices controlled in the normal mode of operation to copulsate and counterpulsate with the heart, respectively, and produce a blood flow waveform corresponding to the blood flow waveform of the heart being assisted. The heart assist device is a pump connected serially between the discharge of a heart ventricle and the vascular system. The pump may be connected to the aorta between the left ventricle discharge immediately adjacent the aortic valve and a ligation in the aorta a short distance from the discharge. This pump has coaxially aligned cylindrical inlet and discharge pumping chambers of the same diameter and a reciprocating piston in one chamber fixedly connected with a reciprocating piston of the other chamber. The piston pump further includes a passageway leading between the inlet and discharge chambers and a check valve in the passageway preventing flow from the discharge chamber into the inlet chamber. There is no flow through the movable element of the piston.”

U.S. Pat. No. 5,702,430 also discloses that “U.S. Pat. No. 4,102,610 to Taboada et al. discloses a magnetically operated constant volume reciprocating pump which can be used as a surgically implantable heart pump or assist. The reciprocating member is a piston carrying a tilting-disk type check valve positioned in a cylinder. While a tilting disk valve results in less turbulence and applied shear to surrounding fluid than a squeezed flexible sack or rotating impeller, the shear applied may still be sufficiently excessive so as to cause damage to red blood cells.”

U.S. Pat. No. 5,702,430 also discloses that “U.S. Pat. Nos. 4,210,409 and 4,375,941 to Child disclose a pump used to assist pumping action of the heart having a piston movable in a cylindrical casing in response to magnetic forces. A tilting-disk type check valve carried by the piston provides for flow of fluid into the cylindrical casing and restricts reverse flow. A plurality of longitudinal vanes integral with the inner wall of the cylindrical casing allow for limited reverse movement of blood around the piston which may result in compression and additional shearing of red blood cells. A second fixed valve is present in the inlet of the valve to prevent reversal of flow during piston reversal.”

U.S. Pat. No. 5,702,430 also discloses that “U.S. Pat. No. 4,965,864 to Roth discloses a linear motor using multiple coils and a reciprocating element containing permanent magnets which is driven by microprocessor-controlled power semiconductors. A plurality of permanent magnets is mounted on the reciprocating member. This design does not provide for self-synchronization of the linear motor in the event the stroke of the linear motor is greater than twice the pole pitch on the reciprocating element. During start-up of the motor, or if magnetic coupling is lost, the reciprocating element may slip from its synchronous position by any multiple of two times the pole pitch. As a result, a sensing arrangement must be included in the design to detect the position of the piston so that the controller will not drive it into one end of the closed cylinder. In addition, this design having equal pole pitch and slot pitch results in a “jumpy” motion of the reciprocating element along its stroke.”

U.S. Pat. No. 5,702,430 also discloses that “In addition to the piston position sensing arrangement discussed above, the Roth design may also include a temperature sensor and a pressure sensor as well as control circuitry responsive to the sensors to produce the intended piston motion. For applications such as implantable blood pumps where replacement of failed or malfunctioning sensors requires open heart surgery, it is unacceptable to have a linear motor drive and controller that relies on any such sensors. In addition, the Roth controller circuit uses only NPN transistors thereby restricting current flow to the motor windings to one direction only.’

‘U.S. Pat. No. 4,541,787 to Delong describes a pump configuration wherein a piston containing a permanent magnet is driven in a reciprocating fashion along the length of a cylinder by energizing a sequence of coils positioned around the outside of the cylinder. However, the coil and control system configurations disclosed only allow current to flow through one individual winding at a time. This does not make effective use of the magnetic flux produced by each pole of the magnet in the piston. To maximize force applied to the piston in a given direction, current must flow in one direction in the coils surrounding the vicinity of the north pole of the permanent magnet while current flows in the opposite direction in the coils surrounding the vicinity of the south pole of the permanent magnet. Further, during starting of the pump disclosed by Delong, if the magnetic piston is not in the vicinity of the first coil energized, the sequence of coils that are subsequently energized will ultimately approach and repel the magnetic piston toward one end of the closed cylinder. Consequently, the piston must be driven into the end of the closed cylinder before the magnetic poles created by the external coils can become coupled with the poles of the magnetic piston in attraction.”

U.S. Pat. No. 5,702,430 also discloses that “U.S. Pat. No. 4,610,658 to Buchwald et al. discloses an implantable fluid displacement peritoneovenous shunt system. The system comprises a magnetically driven pump having a spool piston fitted with a disc flap valve.”

U.S. Pat. No. 5,702,430 also discloses that “U.S. Pat. No. 5,089,017 to Young et al. discloses a drive system for artificial hearts and left ventricular assist devices comprising one or more implantable pumps driven by external electromagnets. The pump utilizes working fluid, such as sulfur hexafluoride to apply pneumatic pressure to increase blood pressure and flow rate.”

U.S. Pat. No. 5,743,854 discloses a device for inducing and localizing epileptiform activity that is comprised of a direct current (DC) magnetic field generator, a DC power source, and sensors adapted to be coupled to a patient's head; this direct current magnetic field generator may be used in conjunction with the anti-mitotic compound of this invention and/or an auxiliary device and/or tubulin and/or microtubules. In one embodiment of the invention, described in claim 7, the sensors “ . . . comprise Foramen Ovale electrodes adapted to be implanted to sense evoked and natural epileptic firings.”

U.S. Pat. No. 5,803,897discloses a penile prosthesis system comprised of an implantable pressurized chamber, a reservoir, a rotary pump, a magnetically responsive rotor, and a rotary magnetic field generator. Claim 1 of this patent describes: “A penile prosthesis system comprising: at least one pressurizable chamber including a fluid port, said chamber adapted to be located within the penis of a patient for tending to make the penis rigid in response to fluid pressure within said chamber; a fluid reservoir; a rotary pump adapted to be implanted within the body of a user, said rotary pump being coupled to said reservoir and to said chamber, said rotary pump including a magnetically responsive rotor adapted for rotation in the presence of a rotating magnetic field, and an impeller for tending to pump fluid at least from said reservoir to said chamber under the impetus of fluid pressure, to thereby pressurize said chamber in response to operation of said pump; and a rotary magnetic field generator for generating a rotating magnetic field, for, when placed adjacent to the skin of said user at a location near said rotary pump, rotating said magnetically responsive rotor in response to said rotating magnetic field, to thereby tend to pressurize said chamber and to render the penis rigid; controllable valve means operable in response to motion of said rotor of said rotary pump, for tending to prevent depressurization of said chamber when said rotating magnetic field no longer acts on said rotor, said controllable valve means comprising a unidirectional check valve located in the fluid path extending between said rotary pump and said port of said chamber.” Such fluid pumping means may be used to facilitate the delivery of the anti-mitotic compound of this invention.

U.S. Pat. No. 5,810,015 describes an implantable power supply that can convert non-electrical energy (such as mechanical, chemical, thermal, or nuclear energy) into electrical energy; the entire disclosure of this United States patent is hereby incorporated by reference into this specification. This power supply may be used to supply energy to the anti-mitotic compound of this invention and/or to tubulin and/or to microtubules.

In column 1 of U.S. Pat. No. 5,810,015, a discussion of “prior art” rechargeable power supplies is presented. It is disclosed in this column 1 that: “Modern medical science employs numerous electrically powered devices which are implanted in a living body. For example, such devices may be employed to deliver medications, to support blood circulation as in a cardiac pacemaker or artificial heart, and the like. Many implantable devices contain batteries which may be rechargeable by transcutaneous induction of electromagnetic fields in implanted coils connected to the batteries. Transcutaneous inductive recharging of batteries in implanted devices is disclosed for example in U.S. Pat. Nos. 3,923,060; 4,082,097; 4,143,661; 4,665,896; 5,279,292; 5,314,453; 5,372,605, and many others.”

U.S. Pat. No. 5,810,015 also discloses that: “Other methods for recharging implanted batteries have also been attempted. For example, U.S. Pat. No. 4,432,363 discloses use of light or heat to power a solar battery within an implanted device. U.S. Pat. No. 4,661,107 discloses recharging of a pacemaker battery using mechanical energy created by motion of an implanted heart valve.” These “other methods” may also be used in the process of this invention.

U.S. Pat. No. 5,810,015 also discloses that: “A number of implanted devices have been powered without batteries. U.S. Pat. Nos. 3,486,506 and 3,554,199 disclose generation of electric pulses in an implanted device by movement of a rotor in response to the patient's heartbeat. U.S. Pat. No. 3,563,245 discloses a miniaturized power supply unit which employs mechanical energy of heart muscle contractions to generate electrical energy for a pacemaker. U.S. Pat. No. 3,456,134 discloses a piezoelectric converter for electronic implants in which a piezoelectric crystal is in the form of a weighted cantilever beam capable of responding to body movement to generate electric pulses. U.S. Pat. No. 3,659,615 also discloses a piezoelectric converter which reacts to muscular movement in the area of implantation. U.S. Pat. No. 4,453,537 discloses a pressure actuated artificial heart powered by a second implanted device attached to a body muscle which in turn is stimulated by an electric signal generated by a pacemaker.” These “other devices” may also be used in the process of this invention.

U.S. Pat. No. 5,810,015 also discloses that: “In spite of all these efforts, a need remains for efficient generation of energy to supply electrically powered implanted devices.” The solution provided by U.S. Pat. No. 5,80,015 is described in claim 1 thereof, which describes: “An implantable power supply apparatus for supplying electrical energy to an electrically powered device, comprising: a power supply unit including: a transcutaneously, invasively rechargeable non-electrical energy storage device (NESD); an electrical energy storage device (EESD); and an energy converter coupling said NESD and said EESD, said converter including means for converting non-electrical energy stored in said NESD to electrical energy and for transferring said electrical energy to said EESD, thereby storing said electrical energy in said EESD.” An implantable ultrasound communicaton system is disclosed in U.S. Pat. No. 5,861,018, the entire disclosure of which is hereby incorporated by reference into this specification. As is disclosed in the abstract of this patent, there is disclosed in such patent “A system for communicating through the skin of a patient, the system including an internal communication device implanted inside the body of a patient and an external communication device. The external communication device includes an external transmitter which transmits a carrier signal into the body of the patient during communication from the internal communication device to the external communication device. The internal communication device includes an internal modulator which modulates the carrier signal with information by selectively reflecting the carrier signal or not reflecting the carrier signal. The external communication device demodulates the carrier signal by detecting when the carrier signal is reflected and when the carrier signal is not reflected through the skin of the patient. When the reflected carrier signal is detected, it is interpreted as data of a first state, and when the reelected carrier signal is not detected, it is interpreted as data of a second state. Accordingly, the internal communication device consumes relatively little power because the carrier signal used to carry the information is derived from the external communication device. Further, transfer of data is also very efficient because the period needed to modulate information of either the first state or the second state onto the carrier signal is the same. In one embodiment, the carrier signal operates in the ultrasound frequency range.”

U.S. Pat. No. 5,861,019, the entire disclosure of which is hereby incorporated by reference into this specification, discloses a telemetry system for communications between an external programmer and an implantable medical device. Claim 1 of this patent describes: “A telemetry system for communications between an external programmer and an implantable medical device, comprising: the external programmer comprising an external telemetry antenna and an external transceiver for receiving uplink telemetry transmissions and transmitting downlink telemetry transmission through the external telemetry antenna; the implantable medical device comprising an implantable medical device housing, an implantable telemetry antenna and an implantable transceiver for receiving downlink transmissions and for transmitting uplink telemetry transmission through the implantable telemetry antenna, the implantable medical device housing being formed of a conductive metal and having an exterior housing surface and an interior housing surface; the implantable medical device housing being formed with a housing recess extending inwardly from the exterior housing surface to a predetermined housing recess depth in the predetermined substrate area of the exterior housing surface for receiving the dielectric substrate therein; wherein the implantable telemetry antenna is a conformal microstrip antenna formed as part of the implantable medical device housing, the microstrip antenna having electrically conductive ground plane and radiator patch layers separated by a dielectric substrate, layer the conductive radiator patch layer having a predetermined thickness and predetermined radiator patch layer dimensions, the patch layer being formed upon one side of the dielectric substrate layer.”

“An extensive description of the historical development of uplink and downlink telemetry transmission formats” is set forth at columns 2 through 5 of U.S. Pat. No. 5,861,019; such telemetry transmission formats may be used in conjunction with the anti-mitotic compound of this invention. As is disclosed in these columns: “An extensive description of the historical development of uplink and downlink telemetry transmission formats and is set forth in the above-referenced '851 and '963 applications and in the following series of commonly assigned patents all of which are incorporated herein by reference in their entireties. Commonly assigned U.S. Pat. No. 5,127,404 to Grevious et al. sets forth an improved method of frame based, pulse position modulated (PPM) of data particularly for uplink telemetry. The frame-based PPM telemetry format increases bandwidth well above simple PIM or pulse width modulation (PWM) binary bit stream transmissions and thereby conserves energy of the implanted medical device. Commonly assigned U.S. Pat. No. 5,168,871 to Grevious et al. sets forth an improvement in the telemetry system of the '404 patent for detecting uplink telemetry RF pulse bursts that are corrupted in a noisy environment. Commonly assigned U.S. Pat. No. 5,292,343 to Blanchette et al. sets forth a further improvement in the telemetry system of the '404 patent employing a hand shake protocol for maintaining the communications link between the external programmer and the implanted medical device despite instability in holding the programmer RF head steady during the transmission. Commonly assigned U.S. Pat. No. 5,324,315 to Grevious sets forth an improvement in the uplink telemetry system of the '404 patent for providing feedback to the programmer to aid in optimally positioning the programmer RF head over the implanted medical device. Commonly assigned U.S. Pat. No. 5,117,825 to Grevious sets forth an further improvement in the programmer RF head for regulating the output level of the magnetic H field of the RF head telemetry antenna using a signal induced in a sense coil in a feedback loop to control gain of an amplifier driving the RF head telemetry antenna. Commonly assigned U.S. Pat. No. 5,562,714 to Grevious sets forth a further solution to the regulation of the output level of the magnetic H field generated by the RF head telemetry antenna using the sense coil current to directly load the H field. Commonly assigned U.S. Pat. No. 5,354,319 to Wybomey et al. sets forth a number of further improvements in the frame based telemetry system of the '404 patent. Many of these improvements are incorporated into MEDTRONIC® Model 9760, 9766 and 9790 programmers. These improvements and the improvements described in the above-referenced pending patent applications are directed in general to increasing the data transmission rate, decreasing current consumption of the battery power source of the implantable medical device, and increasing reliability of uplink and downlink telemetry transmissions.”

U.S. Pat. No. 5,810,015 also discloses that: “The current MEDTRONIC® telemetry system employing the 175 kHz carrier frequency limits the upper data transfer rate, depending on bandwidth and the prevailing signal-to-noise ratio. Using a ferrite core, wire coil, RF telemetry antenna results in: (1) a very low radiation efficiency because of feed impedance mismatch and ohmic losses; 2) a radiation intensity attenuated proportionally to at least the fourth power of distance (in contrast to other radiation systems which have radiation intensity attenuated proportionally to square of distance); and 3) good noise immunity because of the required close distance between and coupling of the receiver and transmitter RF telemetry antenna fields.”

U.S. Pat. No. 5,810,015 also discloses that “These characteristics require that the implantable medical device be implanted just under the patient's skin and preferably oriented with the RF telemetry antenna closest to the patient's skin. To ensure that the data transfer is reliable, it is necessary for the patient to remain still and for the medical professional to steadily hold the RF programmer head against the patient's skin over the implanted medical device for the duration of the transmission. If the telemetry transmission takes a relatively long number of seconds, there is a chance that the programmer head will not be held steady. If the uplink telemetry transmission link is interrupted by a gross movement, it is necessary to restart and repeat the uplink telemetry transmission. Many of the above-incorporated, commonly assigned, patents address these problems.”

U.S. Pat. No. 5,810,015 also discloses that “The ferrite core, wire coil, RF telemetry antenna is not bio-compatible, and therefore it must be placed inside the medical device hermetically sealed housing. The typically conductive medical device housing adversely attenuates the radiated RF field and limits the data transfer distance between the programmer head and the implanted medical device RF telemetry antennas to a few inches.”

U.S. Pat. No. 5,810,015 also discloses that “In U.S. Pat. Nos. 4,785,827 to Fischer, 4,991,582 to Byers et al., and commonly assigned 5,470,345 to Hassler et al. (all incorporated herein by reference in their entireties), the metal can typically used as the hermetically sealed housing of the implantable medical device is replaced by a hermetically sealed ceramic container. The wire coil antenna is still placed inside the container, but the magnetic H field is less attenuated. It is still necessary to maintain the implanted medical device and the external programming head in relatively close proximity to ensure that the H field coupling is maintained between the respective RF telemetry antennas.”

U.S. Pat. No. 5,810,015 also discloses that: “Attempts have been made to replace the ferrite core, wire coil, RF telemetry antenna in the implantable medical device with an antenna that can be located outside the hermetically sealed enclosure. For example, a relatively large air core RF telemetry antenna has been embedded into the thermoplastic header material of the MEDTRONIC® Prometheus programmable IPG. It is also suggested that the RF telemetry antenna may be located in the IPG header in U.S. Pat. No. 5,342,408. The header area and volume is relatively limited, and body fluid may infiltrate the header material and the RF telemetry antenna.”

U.S. Pat. No. 5,810,015 also discloses that: “In U.S. Pat. Nos. 5,058,581 and 5,562,713 to Silvian, incorporated herein by reference in their entireties, it is proposed that the elongated wire conductor of one or more medical lead extending away from the implanted medical device be employed as an RF telemetry antenna. In the particular examples, the medical lead is a cardiac lead particularly used to deliver energy to the heart generated by a pulse generator circuit and to conduct electrical heart signals to a sense amplifier. A modest increase in the data transmission rate to about 8 Kb/s is alleged in the '581 and '713 patents using an RF frequency of 10-300 MHz. In these cases, the conductor wire of the medical lead can operate as a far field radiator to a more remotely located programmer RF telemetry antenna. Consequently, it is not necessary to maintain a close spacing between the programmer RF telemetry antenna and the implanted cardiac lead antenna or for the patient to stay as still as possible during the telemetry transmission.”

U.S. Pat. No. 5,810,015 also discloses that: “However, using the medical lead conductor as the RF telemetry antenna has several disadvantages. The radiating field is maintained by current flowing in the lead conductor, and the use of the medical lead conductor during the RF telemetry transmission may conflict with sensing and stimulation operations. RF radiation losses are high because the human body medium is lossy at higher RF frequencies. The elongated lead wire RF telemetry antenna has directional radiation nulls that depend on the direction that the medical lead extends, which varies from patient to patient. These considerations both contribute to the requirement that uplink telemetry transmission energy be set artificially high to ensure that the radiated RF energy during the RF uplink telemetry can be detected at the programmer RF telemetry antenna. Moreover, not all implantable medical devices have lead conductor wires extending from the device.”

U.S. Pat. No. 5,810,015 also discloses that: “A further U.S. Pat. No. 4,681,111 to Silvian, incorporated herein by reference in its entirety, suggests the use of a stub antenna associated with the header as the implantable medical device RF telemetry antenna for high carrier frequencies of up to 200 MHz and employing phase shift keying (PSK) modulation. The elimination of the need for a VCO and a bit rate on the order of 2-5% of the carrier frequency or 3.3-10 times the conventional bit rate are alleged.”

U.S. Pat. No. 5,810,015 also discloses that: “At present, a wide variety of implanted medical devices are commercially released or proposed for clinical implantation. Such medical devices include implantable cardiac pacemakers as well as implantable cardioverter-defibrillators, pacemaker-cardioverter-defibrillators, drug delivery pumps, cardiomyostimulators, cardiac and other physiologic monitors, nerve and muscle stimulators, deep brain stimulators, cochlear implants, artificial hearts, etc. As the technology advances, implantable medical devices become ever more complex in possible programmable operating modes, menus of available operating parameters, and capabilities of monitoring increasing varieties of physiologic conditions and electrical signals which place ever increasing demands on the programming system.”

U.S. Pat. No. 5,810,015 also discloses that: “It remains desirable to minimize the time spent in uplink telemetry and downlink transmissions both to reduce the likelihood that the telemetry link may be broken and to reduce current consumption.” “Moreover, it is desirable to eliminate the need to hold the programmer RF telemetry antenna still and in proximity with the implantable medical device RF telemetry antenna for the duration of the telemetry transmission. As will become apparent from the following, the present invention satisfies these needs.”

The solution to this problem is presented, e.g., in claim 1 of U.S. Pat. No. 5,861,019. This claim describes “A telemetry system for communications between an external programmer and an implantable medical device, comprising: the external programmer comprising an external telemetry antenna and an external transceiver for receiving uplink telemetry transmissions and transmitting downlink telemetry transmission through the external telemetry antenna; the implantable medical device comprising an implantable medical device housing, an implantable telemetry antenna and an implantable transceiver for receiving downlink transmissions and for transmitting uplink telemetry transmission through the implantable telemetry antenna, the implantable medical device housing being formed of a conductive metal and having an exterior housing surface and an interior housing surface; the implantable medical device housing being formed with a housing recess extending inwardly from the exterior housing surface to a predetermined housing recess depth in the predetermined substrate area of the exterior housing surface for receiving the dielectric substrate therein; wherein the implantable telemetry antenna is a conformal microstrip antenna formed as part of the implantable medical device housing, the microstrip antenna having electrically conductive ground plane and radiator patch layers separated by a dielectric substrate, layer the conductive radiator patch layer having a predetermined thickness and predetermined radiator patch layer dimensions, the patch layer being formed upon one side of the dielectric substrate layer.”

U.S. Pat. No. 5,945,762, the entire disclosure of which is hereby incorporated by reference into this specification, discloses an external transmitter adapted to magnetically excite an implanted receiver coil; such an implanted receiver coil may be disposed near, e.g., the anti-mitotic compound of this invention and/or other devices and/or tubulin and/or microtubules. Claim 1 of this patent describes “An external transmitter adapted for magnetically exciting an implanted receiver coil, causing an electrical current to flow in the implanted receiver coil, comprising: (a) a support; (b) a magnetic field generator that is mounted to the support; and (c) a prime mover that is drivingly coupled to an element of the magnetic field generator to cause said element of the magnetic field generator to reciprocate, in a reciprocal motion, said reciprocal motion of said element of the magnetic field generator producing a varying magnetic field that is adapted to induce an electrical current to flow in the implanted receiver coil.”

U.S. Pat. No. 5,954,758, the entire disclosure of which is hereby incorporated by reference into this specification, claims an implantable electrical stimulator comprised of an implantable radio frequency receiving coil, an implantable power supply, an implantable input signal generator, an implantable decoder, and an implantable electrical stimulator. Claim 1 of this patent describes “A system for transcutaneously telemetering position signals out of a human body and for controlling a functional electrical stimulator implanted in said human body, said system comprising: an implantable radio frequency receiving coil for receiving a transcutaneous radio frequency signal; an implantable power supply connected to said radio frequency receiving coil, said power supply converting received transcutaneous radio frequency signals into electromotive power; an implantable input signal generator electrically powered by said implantable power supply for generating at least one analog input movement signal to indicate voluntary bodily movement along an axis; an implantable encoder having an input operatively connected with said implantable input signal generator for encoding said movement signal into output data in a preselected data format; an impedance altering means connected with said encoder and said implantable radio frequency signal receiving coil to selectively change an impedance of said implantable radio frequency signal receiving coil; an external radio frequency signal transmit coil inductively coupled with said implantable radio frequency signal receiving coil, such that impedance changes in said implantable radio frequency signal receiving coil are sensed by said external radio frequency signal transmit coil to establish a sensed modulated movement signal in said external transmit coil; an external control system electrically connected to said external radio frequency transmit coil for monitoring said sensed modulated movement signal in said external radio frequency transmit coil, said external control system including: a demodulator for recovering the output data of said encoder from the sensed modulated ovement signal of said external transmit coil, a pulse width algorithm means for applying a preselected pulse width algorithm to the recovered output data to derive a first pulse width, an amplitude algorithm means for applying an amplitude algorithm to the recovered output data to derive a first amplitude therefrom, an interpulse interval algorithm means for applying an interpulse algorithm to the recovered output data to derive a first interpulse interval therefrom; and, a stimulation pulse train signal generator for generating a stimulus pulse train signal which has the first pulse width and the first pulse amplitude; an implantable functional electrical stimulator for receiving said stimulation pulse train signal from said stimulation pulse train signal generator and generating stimulation pulses with the first pulse width, the first pulse amplitude, and separated by the first interpulse interval; and, at least one electrode operatively connected with the functional electrical stimulator for applying said stimulation pulses to muscle tissue of said human body.”

U.S. Pat. No. 6,006,133, the entire disclosure of which is hereby incorporated by reference into this specification, describes an implantable medical device comprised of a hermetically sealed housing.” Such a hermetically sealed housing may be used to contain, e.g., the anti-mitotic compound of this invention.

U.S. Pat. No. 6,083,166, the entire disclosure of which is hereby incorporated by reference into this specification, discloses an ultrasound transmitter for use with a surgical device. This ultrasound transmitter may be used, e.g., to affect the anti-mitotic compound of this invention and/or tubulin and/or microtubules.

U.S. Pat. No. 6,152,882, the entire disclosure of which is hereby incorporated by reference into this specification, discloses an implantable electroporation unit, an implantable proble electrode, an implantable reference electrode, and an an amplifier unit; this electroporation unit may be used to treat, e.g., cancer cells in conjunction with the anti-mitotic compound of this invention. Claim 35 of this patent describes: “Apparatus for measurement of monophasic action potentials from an excitable tissue including a plurality of cells, the apparatus comprising: at least one probe electrode placeable adjacent to or in contact with a portion of said excitable tissue; at least one reference electrode placeable proximate said at least one probe electrode; an electroporating unit electrically connected to said at least one probe electrode and said at least one reference electrode for controllably applying to at least some of said cells subjacent said at least one probe electrode electrical current pulses suitable for causing electroporation of cell membranes of said at least some of said cells; and an amplifier unit electrically connected to said at least one probe electrode and to said at least one reference electrode for providing an output signal representing the potential difference between said probe electrode and said reference electrode.”

U.S. Pat. No. 6,169,925, the entire disclosure of which is hereby incorporated by reference into this specification, describes a transceiver for use in communication with an implantable medical device. Claim 1 of this patent describes: “An external device for use in communication with an implantable medical device, comprising: a device controller; a housing; an antenna array mounted to the housing; an RF transceiver operating at defined frequency, coupled to the antenna array; means for encoding signals to be transmitted to the implantable device, coupled to an input of the transceiver; means for decoding signals received from the implantable device, coupled to an output of the transceiver; and means for displaying the decoded signals received from the implantable device; wherein the antenna array comprises two antennas spaced a fraction of the wavelength of the defined frequency from one another, each antenna comprising two antenna elements mounted to the housing and located orthogonal to one another; and wherein the device controller includes means for selecting which of the two antennas is coupled to the transceiver.” Such a transceiver, in combination with an implantable sensor, may be used in conjunction with the anti-mitotic compound of this invention and/or tubulin and/or microtubules and/or one or more other implanted devices.

U.S. Pat. No. 6,185,452, the entire disclosure of which is hereby incorporated by reference into this specification, claims a device for stimulating internal tissue, wherein such device is comprised of: “a sealed elongate housing configured for implantation in said patient's body, said housing having an axial dimension of less than 60 mm and a lateral dimension of less than 6 mm; power consuming circuitry carried by said housing including at least one electrode extending externally of said housing, said power consuming circuitry including a capacitor and pulse control circuitry for controlling (1) the charging of said capacitor and (2) the discharging of said capacitor to produce a current pulse through said electrode; a battery disposed in said housing electrically connected to said power consuming circuitry for powering said pulse control circuitry and charging said capacitor, said battery having a capacity of at least one microwatt-hour; an internal coil and a charging circuit disposed in said housing for supplying a charging current to said battery; an external coil adapted to be mounted outside of said patient's body; and means for energizing said external coil to generate an alternating magnetic field for supplying energy to said charging circuit via said internal coil.” Such capacitative discharge energy may be used to affect either the anti-mitotic compound of this invention and/or tubulin and/or microtubules.

U.S. Pat. No. 6,235,024, the entire disclosure of which is hereby incorporated by reference into this specification, discloses an implantable high frequency energy generator; such high-frequency energy may be used to affect either the anti-mitotic compound of this invention, tubulin, microtubules, and/or one or more other implanted devices. Claim 1 of this patent describes: “A catheter system comprising: an elongate catheter tubing having a distal section, a distal end, a proximal end, and at least one lumen extending between the distal end and the proximal end; a handle attached to the proximal end of said elongate catheter tubing, wherein the handle has a cavity; an ablation element mounted at the distal section of the elongate catheter tubing, the ablation element having a wall with an outer surface and an inner surface, wherein the outer surface is covered with an outer member made of a first electrically conductive material and the inner surface is covered with an inner member made of a second electrically conductive material, and wherein the wall comprises an ultrasound transducer; an electrical conducting means having a first and a second electrical wires, wherein the first electrical wire is coupled to the outer member and the second electrical wire is coupled to the inner member of the ablation element; and a high frequency energy generator means for providing a radiofrequency energy to the ablation element through a first electrical wire of the electrical conducting means.”

An implantable light-generating apparatus is described in claim 16 of U.S. Pat. No. 6,363,279, the entire disclosure of which is hereby incorporated by reference into this specification. In one embodiment, the compound of this invention is comprised of a photolytic linker which is caused to disassociate upon being exposed to specified light energy. As is disclosed in such claim 16, this patent provides a “Heart control apparatus, comprising circuitry for generating a non-excitatory stimulus, and stimulus application devices for applying to a heart or to a portion thereof said non-excitatory stimulus, wherein the circuitry for generating a non-excitatory stimulus generates a stimulus which is unable to generate a propagating action potential and wherein said circuitry comprises a light-generating apparatus for generating light.”

An implantable ultrasound probe is described in claim 1 of U.S. Pat. No. 6,421,565, the entire disclosure of which is hereby incorporated by reference into this specification. Such ultrasound may be used, e.g., to treat the microtubules of cancer cells; and this treatment may be combined, e.g., with the anti-mitotic compounds of this invention.

Claim 1 of U.S. Pat. No. 6,421,565 describes: “An implantable cardiac monitoring device comprising: an A-mode ultrasound probe adapted for implantation in a right ventricle of a heart, said ultrasound probe emitting an ultrasound signal and receiving at least one echo of said ultrasound signal from at least one cardiac segment of the left ventricle; a unit connected to said ultrasound probe for identifying a time difference between emission of said ultrasound signal and reception of said echo and, from said time difference, determining a position of said cardiac segment, said cardiac segment having a position which, at least when reflecting said ultrasound signal, is correlated to cardiac performance, and said unit deriving an indication of said cardiac performance from said position of said cardiac segment.”

An implantable stent that contains a tube and several optical emitters located on the inner surface of the tube is disclosed in U.S. Pat. No. 6,488,704, the entire disclosure of which is hereby incorporated by reference into this specification. One may use one or more of the implantable devices described in U.S. Pat. No. 6,488,704 together with the anti-mitotic compound of this invention and/or tubulin and/or microtubules and/or another in vivo device.

Claim 1 of U.S. Pat. No. 6,488,704 describes “1. An implantable stent which comprises: (a) a tube comprising an inner surface and an outer surface, and (b) a multiplicity of optical radiation emitting means adapted to emit radiation with a wavelength from about 30 nanometers to about 30 millimeters, and a multiplicity of optical radiation detecting means adapted to detect radiation with a wavelength of from about 30 nanometers to about 30 millimeters, wherein said optical radiation emitting means and said optical radiation detecting means are disposed on the inside surface of said tube.”

Many other implantable devices and configurations are described in the claims of U.S. Pat. No. 6,488,704. These devices and configurations may be used in conjunction with the anti-mitotic compound of this invention, and/or tubulin, and/or microtubules, and/or other auxiliary, implanted deivce.

Thus, e.g., claim 2 of U.S. Pat. No. 6,488,704 discloses that the “ . . . implantable stent is comprised of a flexible casing with an inner surface and an outer surface.” Claim 3 of such patent discloses that the case may be “ . . . comprised of fluoropolymer.” Claim 4 of such patent discloses that the casing may be “ . . . optically impermeable.”

Thus, e.g., claim 10 of U.S. Pat. No. 6,488,704 discloses an embodiment in which an implantable stent contains “ . . . telemetry means for transmitting a signal to a receiver located external to said implantable stent.” The telemetry means may be adapted to receive “ . . . a signal from a transmitter located external to said implantable stent (see claim 11); and such signal may be a radio-frequency signal (see claims 12 and 13). The implantable stent may also comprise “ . . . telemetry means for transmitting a signal to a receiver located external to said implantable stent”(see claim 22), and/or “ . . . telemetry means for receiving a signal from a transmitter located external to said implantable stent” (see claim 23), and/or “ . . . a controller operatively connected to said means for transmitting a signal to said receiver, and operatively connected to said means for receiving a signal from said transmitter” (see claim 24).

Referring again to U.S. Pat. No. 6,488,704, the entire disclosure of which is hereby incorporated by reference into this specification, the implantable stent may be comprised of an arithmetic unit (see claim 37 of such patent), and such arithmetic unit may be “ . . . comprised of means for receiving signals from said optical radiation detecting means” (see claim 38), and/or “ . . . means for calculating the concentration of components in an analyte disposed within said implantable stent (see claim 39). In one embodiment, “said means for calculating the concentration of components in said analyte calculates concentrations of said components in said analyte based upon optimum optical path lengths for different wavelengths and values of transmitted light (see claim 40).

Referring again to U.S. Pat. No. 6,488,704, the implantable stent may contain a power supply (see claim 41 thereof) which may contain a battery (see claim 42) which, in one embodiment, is a lithium-iodine battery (see claim 43).

U.S. Pat. No. 6,585,763, the entire disclosure of which is hereby incorporated by reference into this specification, describes in its claim 1 “ . . . a vascular graft comprising: a biocompatible material formed into a shape having a longitudinal axis to enclose a lumen disposed along said longitudinal axis of said shape, said lumen positioned to convey fluid through said vascular graft; a first transducer coupled to a wall of said vascular graft; and an implantable circuit for receiving electromagnetic signals, said implantable circuit coupled to said first transducer, said first transducer configured to receive a first energy from said circuit to emit a second energy having one or more frequencies and power levels to alter said biological activity of said medication in said localized area of said body subsequent to implantation of said first transducer in said body near said localized area.” One may use the means for “ . . . altering said biological activity of said medication . . . ” in the process of this invention. The transducer may be selected from the group consisting of “ . . . an ultrasonic transducer, a plurality of light sources, an electric field transducer, an electromagnetic transducer, and a resistive heating transducer” (see claim 2), it may comprise a coil (see claim 3), it may comprise “ . . . a regular solid including piezoelectric material, and wherein a first resonance frequency, being of said one or more frequencies, is determined by a first dimension of said regular solid and a second resonance frequency, being of said one or more frequencies, is determined by a second dimension of said regular solid and further including a first electrode coupled to said regular solid and a second electrode coupled to said regular solid” (see claim 4).

U.S. Pat. No. 6,605,089, the entire disclosure of which is hereby incorporated by reference into this specification, discloses an implantable bone growth promoting device. Claim 1 of this patent describes “A device for placement into and between at least two adjacent bone masses to promote bone growth therebetween, said device comprising: an implant having opposed first and second surfaces for placement between and in contact with the adjacent bone masses, a mid-longitudinal axis, and a hollow chamber between said first and second surfaces, said hollow chamber being adapted to hold bone growth promoting material, said hollow chamber being along at least a portion of the mid-longitudinal axis of said implant, each of said first and second surfaces having at least one opening in communication with said hollow chamber into which bone from the adjacent bone masses grows; and an energizer for energizing said implant, said energizer being sized and configured to promote bone growth from adjacent bone mass to adjacent bone mass through said first and second surfaces and through at least a portion of said hollow chamber at the mid-longitudinal axis.” The implant may have a coil wrapped around it (see claim 6), a portion of the coil may be “ . . . in the form of an external thread on at least a portion of said first and second surfaces of said implant” (see claim 7), the “external thread” may be energized by the “energizer” (claim 8) by conducting “ . . . electromagnetic energy to said interior space . . . ” of the energizer (claim 9). One may use such “energizer” in the process of this invention.

Referring again to U.S. Pat. No. 6,605,089, and to the implant claimed therein, the implant may contain “ . . . a power supply delivering an electric charge” (see claim 14), and it may comprise “ . . . a first portion that is electrically conductive for delivering said electrical charge to at least a portion of the adjacent bone masses and said energizer delivers negative electrical charge to said first portion of said implant” (see claim 15). Additionally, the implant may also contain “ . . . a controller for controlling the delivery of said electric charge” that is disposed within the implant (see claim 18), that “ . . . includes one of a wave form generator and a voltage generator” (see claim 19), and that “ . . . provides for the delivery of one of an alternating current, a direct current, and a sinusoidal current” (see claim 21).

U.S. Pat. No. 6,641,520, the entire disclosure of which is hereby incorporated by reference into this specification, discloses a magnetic field generator for providing a static or direct current magnetic field generator.; the magnetic field generator described in this patent may be used in conjunction the anti-mitotic compound and/or tubulin and/or microtubules. In column 1 of this patent, some “prior art” magnetic field generators were described; and they also may be so used. It was stated in such column 1 that: “There has recently been an increased interest in therapeutic application of magnetic fields. There have also been earlier efforts of others in this area. The recent efforts, as well as those earlier made, can be categorized into three general types, based on the mechanism for generating and applying the magnetic field. The first type were what could be generally referred to as systemic applications. These were large, tubular mechanisms which could accommodate a human body within them. A patient or recipient could thus be subjected to magnetic therapy through their entire body. These systems were large, cumbersome and relatively immobile. Examples of this type of therapeutic systems included U.S. Pat. Nos. 1,418,903; 4,095,588; 5,084,003; 5,160,591; and 5,437,600. A second type of system was that of magnetic therapeutic applicator systems in the form of flexible panels, belts or collars, containing either electromagnets or permanent magnets. These applicator systems could be placed on or about portion of the recipient's body to allow application of the magnetic therapy. Because of their close proximity to the recipients body, considerations limited the amount and time duration of application of magnetic therapy. Examples of this type system were U.S. Pat. Nos. 4,757,804; 5,084,003 and 5,344,384. The third type of system was that of a cylindrical or toroidal magnetic field generator, often small and portable, into which a treatment recipient could place a limb to receive electromagnetic therapy. Because of size and other limitations, the magnetic field strength generated in this type system was usually relatively low. Also, the magnetic field was a time varying one. Electrical current applied to cause the magnetic field was time varying, whether in the form of simple alternating current waveforms or a waveform composed of a series of time-spaced pulses.”

The magnetic field generator claimed in U.S. Pat. No. 6,641,520 comprised “ . . . a magnetic field generating coil composed of a wound wire coil generating the static magnetic field in response to electrical power; a mounting member having the coil mounted thereon and having an opening therethrough of a size to permit insertion of a limb of the recipient in order to receive electromagnetic therapy from the magnetic field coil; an electrical power supply furnishing power to the magnetic field coil to cause the coil to generate a static electromagnetic field within the opening of the mounting member for application to the recipient's limb; a level control mechanism providing a reference signal representing a specified electromagnetic field strength set point for regulating the power furnished to the magnetic field coil; a field strength sensor detecting the static electromagnetic field strength generated by the magnetic field coil and forming a field strength signal representing the detected electromagnetic field strength in the opening in the mounting member; a control signal generator receiving the field strength signal from the field strength sensor and the reference signal from the level control mechanism representing a specified electromagnetic field strength set point; and the control signal generator forming a signal to regulate the power flowing from the electrical power supply to the magnetic field coil.”

An implantable sensor is disclosed in U.S. Pat. No. 6,491,639, the entire disclosure of which is hereby incorporated by reference into this specification; this sensor also may be used in conjunction with the anti-mitotic compound of this invention, and/or tubulin, and/or microtubules. Claim 1 of such patent describes: “An implantable medical device including a sensor for use in detecting the hemodynamic status of a patient comprising: a hermetic device housing enclosing device electronics for receiving and processing data; and said device housing including at least one recess and a sensor positioned in said at least one recess.” Claim 10 of such patent describes “10. An implantable medical device including a hemodynamic sensor for monitoring arterial pulse amplitude comprising: a device housing; a transducer comprising a light source and a light detector positioned exterior to said device housing responsive to variations in arterial pulse amplitude; and wherein said light detector receives light originating from said light source and reflected from arterial vasculature of a patient and generates a signal which is indicative of variations in the reflected light caused by the expansion and contraction of said arterial vasculature. “Claim 14 of such patent describes: “14. An implantable medical device including a hemodynamic sensor for monitoring arterial pulse amplitude comprising: a device housing; and an ultrasound transducer associated with said device housing responsive to variations in arterial pulse amplitude.” Claim 15 of such patent describes: “15. An implantable medical device including a hemodynamic sensor for monitoring arterial pulse amplitude comprising: a device housing; and a transducer associated with said device housing responsive to variations in arterial pulse amplitude, said device housing having at least one substantially planar face and said transducer is positioned on said planar face.” Claim 17 of such patent describes “ . . . an implantable pulse generator . . . ’

U.S. Pat. No. 6,663,555, the entire disclosure of which is incorporated by reference into this specification, also claims a magnetic field generator; this magnetic field generator may be used in conjunction with the anti-mitotic compound of this invention and/or tubulin and/or microtubules. Claim 1 of this patent describes: “A magnet keeper-shield assembly for housing a magnet, said magnet keeper-shield assembly comprising: a keeper-shield comprising a material substantially permeable to a magnetic flux; a cavity in the keeper-shield, said cavity comprising an inner side wall and a base, and said cavity being adapted to accept a magnet having a front and a bottom face; an actuator extending through the base; a plurality of springs extending through the base, said springs operative to exert a force in a range from about 175 pounds to about 225 pounds on the bottom face of the magnet in a retracted position, and wherein said magnet produces at least about 118 gauss at a distance of about 10 cm from the front face in the extended position and produces at most about 5 gauss at a distance less than or equal to about 22 cm from the front face in the retracted position.”

Published United States patent application US2002/0182738 discloses an implantable flow cytometer; the entire disclosure of this published United States patent application is hereby incorporated by reference into this specification. Claim 1 of this patent describes “A flow cytometer comprising means for sampling cellular material within a body, means for marking cells within said bodily fluid with a marker to produce marked cells, means for analyzing said marked cells, a first means for removing said marker from said marked cells, a second means for removing said marker from said marked cells, means for sorting said cells within said bodily fluid to produce sorted cells, and means for maintaining said sorted cells cells in a viable state.”

Referring again to published United States patent application US 2002/0182738, the implantable flow cytometer may contain “ . . . a first control valve operatively connected to said first means for removing said marker from said marked cells and to said second means for removing said marker from said marked cells . . . ” (see claim 3), a controller connected to the first control valve (claim 4), a second control valve (claim 5), a third control valve (claim 6), a dye separator (claims 7 and 8), an analyzer for testing blood purity (claim 9), etc.

A similar flow cytometer is disclosed in published United States patent application US 2003/0036718, the entire disclosure of which is also hereby incorporated by reference into this specification.

Published United States patent application US 2003/0036776, the entire disclosure of which is hereby incorporated by reference into this specification, discloses an MRI-compatible implantable device. Claim 1 of this patent describes “A cardiac assist device comprising means for connecting said cardiac assist device to a heart, means for furnishing electrical impulses from said cardiac assist device to said heart, means for ceasing the furnishing of said electrical impulses to said heart, means for receiving pulsed radio frequency fields, means for transmitting and receiving optical signals, and means for protecting said heart and said cardiac assist device from currents induced by said pulsed radio frequency fields, wherein said cardiac assist device contains a control circuit comprised of a parallel resonant frequency circuit and means for activating said parallel resonant frequency circuit.” The “ . . . means for activating said parallel resonant circuit . . . ” may contain “ . . . comprise optical means (see claim 2) such as an optical switch (claim 3) comprised of “ . . . a pin type diode . . . ” (claim 4) and connected to an optical fiber (claim 5). The optical switch may be “ . . . activated by light from a light source . . . ” (claim 6), and it may be located with a biological organism (claim 7). The light source may be located within the biological organism (claim 9), and it may provide “ . . . light with a wavelength of from about 750 to about 850 nanometers . . . ”

Polymeric Carriers and/or Delivery Systems

The anti-mitotic compound of this invention may be used in conjunction with prior art polymeric carriers and/or delivery systems comprised of polymeric material. In one embodiment, the polymeric material 14 is preferably comprised of one or more anti-mitotic compounds that are adapted to be released from the polymeric material wherein the polymeric material is disposed within a biological organism. The polymeric material may be, e.g., any of the drug eluting polymers known to those skilled in the art.

By way of illustration, and referring to U.S. Pat. No. 3,279,996 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be silicone rubber. This patent claims “An implantate for releasing a drug in the tissues of a living organism comprising a drug enclosed in a capsule of silicone rubber, . . . said drug being soluble in and capable of diffusing through said silicone rubber to the outer surface of said capsule . . . ” One may use, as the anti-mitotic compound a material that is soluble in and capable of diffusing through the polymeric material.

At column 1 of U.S. Pat. No. 3,279,996, other “carrier agents” which may be used as polymeric material are also disclosed, including “ . . . beeswax, peanut oil, stearates, etc.” Any of these “carrier agents” may be used as the polymeric material.

By way of further illustration, and as is disclosed in U.S. Pat. No. 4,191,741 (the entire disclosure of which is hereby incorporated by reference into this specification), one may use dimethylpolsiloxane rubber as the polymeric material. This patent claims “A solid, cylindrical, subcutaneous implant for improving the rate of weight gain of ruminant animals which comprises (a) a biocompatible inert core having a diameter of from about 2 to about 10 mm. and (b) a biocompatible coating having a thickness of from about 0.2 to about 1 mm., the composition of said coating comprising from about 5 to about 40 percent by weight of estradiol and from about 95 to about 60 percent by weight of a dimethylpolysiloxane rubber.”

In column 1 of U.S. Pat. No. 4,191,741, other materials which may be used as the polymeric material are disclosed. Thus, it is stated in such patent that “Long et al. U.S. Pat. No. 3,279,996 describes an implant for releasing a drug in the tissues of a living organism comprising the drug enclosed in a capsule formed of silicone rubber. The drug migrates through the silicone rubber wall and is slowly released into the living tissues. A number of biocompatible silicone rubbers are described in the Long et al. patent. When a drug delivery system such as that described in U.S. Pat. No. 3,279,996 is used in an effort to administer estradiol to a ruminant animal a number of problems are encountered. For example, an excess of the drug is generally required in the hollow cavity of the implant. Also, it is difficult to achieve a constant rate of administration of the drug over a long time period such as from 200 to 400 days as would be necessary for the daily administration of estradiol to a growing beef animal. Katz et al. U.S. Pat. No. 4,096,239 describes an implant pellet containing estradiol or estradiol benzoate which has an inert spherical core and a uniform coating comprising a carrier and the drug. The coating containing the drug must be both biocompatible and biosoluble, i.e., the coating must dissolve in the body fluids which act upon the pellet when it is implanted in the body. The rate at which the coating dissolves determines the rate at which the drug is released. Representative carriers for use in the coating material include cholesterol, solid polyethylene glycols, high molecular weight fatty acids and alcohols, biosoluble waxes, cellulose derivatives and solid polyvinyl pyrrolidone.” The polymeric material used with the anti-mitotic compound is, in one embodiment, both biocompatible and biosoluble.

By way of yet further illustration, and referring to U.S. Pat. No. 4,429,080 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be a synthetic absorbable copolymer formed by copolymerizing glycolide with trimethylene carbonate.

By way of yet further illustration, and referring to U.S. Pat. No. 4,581,028 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be selected from the group consisting of polyester (such as Dacron), polytetrafluoroethylene, polyurethane silicone-based material, and polyamide. The polymeric material of this patent is comprised “ . . . of at least one antimicrobial agent selected from the group consisting of the metal salts of sulfonamides.” In one embodiment, the polymeric material is comprised of an antimicrobial agent.

By way of yet further illustration, and referring to U.S. Pat. No. 4,481,353, (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be the bioresorbable polyester disclosed in such patent. U.S. Pat. No. 4,481,353 claims “A bioresorbable polyester in which monomeric subunits are arranged randomly in the polyester molecules, said polyester comprising the condensation reaction product of a Krebs Cycle dicarboxylic acid or isomer or anhydride thereof, chosen for the group consisting of succinic acid, fumaric acid, oxaloacetic acid, L-malic acid, and D-malic acid, a diol having 2, 4, 6, or 8 carbon atoms, and an alpha-hydroxy carboxylic acid chosen from the group consisting of glycolic acid, L-lactic acid and D-lactic acid.”

By way of yet further illustration, and referring to U.S. Pat. No. 4,846,844 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be a silicone polymer matrix in which an anabolic agent (such as an anabolic steroid, or estradiol) is disposed. This patent claims “An implant adapted for the controlled release of an anabolic agent, said implant comprising a silicone polymer matrix, an anabolic agent in said polymer matrix, and an antimicrobial coating, wherein the coating comprises a first-applied non-vulcanizing silicone fluid and a subsequently applied antimicrobial agent in contact with said fluid.”

By way of yet further illustration, and referring to U.S. Pat. No. 4,916,193 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be a copolymer containing carbonate repeat units and ester repeat units (see, e.g., claim 1 of the patent). As disclosed in column 2 of the patent, it may also be “collagen,” “homopolymers and copolymers of glycolic acid and lactic acid,” “alpha-hydroxy carboxylic acids in conjunction with Krebs cycle dicarboxylic acids and aliphatic diols,” “polycarbonate-containing polymers,” and “high molecular weight fiber-forming crystalline copolymers of lactide and glycolide.” Thus, it is disclosed in such column 2 that: “Various polymers have been proposed for use in the fabrication of bioresorbable medical devices. Examples of absorbable materials used in nerve repair include collagen as disclosed by D. G. Kline and G. J. Hayes, “The Use of a Resorbable Wrapper for Peripheral Nerve Repair, Experimental Studies in Chimpanzees”, J. Neurosurgery 21, 737 (1964). Artandi et al., U.S. Pat. No. 3,272,204 (1966) reports the use of collagen protheses that are reinforced with nonabsorbable fabrics. These articles are intended to be placed permanently in a human body. However, one of the disadvantages inherent with collagenous materials, whether utilized alone or in conjunction with biodurable materials, is their potential antigenicity. Other biodegradable polymers of particular interest for medical implantation purposes are homopolymers and copolymers of glycolic acid and lactic acid. A nerve cuff in the form of a smooth, rigid tube has been fabricated from a copolymer of lactic and glycolic acids [The Hand; 10 (3) 259 (1978)]. European patent application No. 118-458-A discloses biodegradable materials used in organ protheses or artificial skin based on poly-L-lactic acid and/or poly-DL-lactic acid and polyester or polyether urethanes. U.S. Pat. No. 4,481,353 discloses bioresorbable polyester polymers, and composites containing these polymers, that are also made up of alpha-hydroxy carboxylic acids, in conjunction with Krebs cycle dicarboxylic acids and aliphatic diols. These polyesters are useful in fabricating nerve guidance channels as well as other surgical articles such as sutures and ligatures. U.S. Pat. Nos. 4,243,775 and 4,429,080 disclose the use of polycarbonate-containing polymers in certain medical applications, especially sutures, ligatures and haemostatic devices. However, this disclosure is clearly limited only to “AB” and “ABA” type block copolymers where only the “B” block contains poly(trimethylene carbonate) or a random copolymer of glycolide with trimethylene carbonate and the “A” block is necessarily limited to glycolide. In the copolymers of this patent, the dominant portion of the polymer is the glycolide component. U.S. Pat. No. 4,157,437 discloses high molecular weight, fiber-forming crystalline copolymers of lactide and glycolide which are disclosed as useful in the preparation of absorbable surgical sutures. The copolymers of this patent contain from about 50 to 75 wt. % of recurring units derived from glycolide.”

By way of further illustration, and referring to U.S. Pat. No. 5,176,907 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be the poly-phosphoester-urethane) described and claimed in claim 1 of such patent. Furthermore, the polymeric material may be one or more of the biodegradable polymers discussed in columns 1 and 2 of such patent. As is disclosed in such columns 1 and 2: “Polymers have been used as carriers of therapeutic agents to effect a localized and sustained release (Controlled Drug Delivery, Vol. I and II, Bruck, S. D., (ed.), CRC Press, Boca Raton, Fla., 1983; Leong, et al., Adv. Drug Delivery Review, 1:199, 1987). These anti-mitotic compounddelivery systems simulate infusion and offer the potential of enhanced therapeutic efficacy and reduced systemic toxicity.” The polymeric material may be such a poly-phosphoester-urethane.

U.S. Pat. No. 5,176,907 also discloses “For a non-biodegradable matrix, the steps leading to release of the anti-mitotic compoundare water diffusion into the matrix, dissolution of the therapeutic agent, and out-diffusion of the anti-mitotic compound through the channels of the matrix. As a consequence, the mean residence time of the anti-mitotic compoundexisting in the soluble state is longer for a non-biodegradable matrix than for a biodegradable matrix where a long passage through the channels is no longer required. Since many pharmaceuticals have short half-lives it is likely that the anti-mitotic compound is decomposed or inactivated inside the non-biodegradable matrix before it can be released. This issue is particularly significant for many bio-macromolecules and smaller polypeptides, since these molecules are generally unstable in buffer and have low permeability through polymers. In fact, in a non-biodegradable matrix, many bio-macromolecules will aggregate and precipitate, clogging the channels necessary for diffusion out of the carrier matrix. This problem is largely alleviated by using a biodegradable matrix which allows controlled release of the therapeutic agent. Biodegradable polymers differ from non-biodegradable polymers in that they are consumed or biodegraded during therapy. This usually involves breakdown of the polymer to its monomeric subunits, which should be biocompatible with the surrounding tissue. The life of a biodegradable polymer in vivo depends on its molecular weight and degree of cross-linking; the greater the molecular weight and degree of crosslinking, the longer the life. The most highly investigated biodegradable polymers are polylactic acid (PLA), polyglycolic acid (PGA), polyglycolic acid (PGA), copolymers of PLA and PGA, polyamides, and copolymers of polyamides and polyesters. PLA, sometimes referred to as polylactide, undergoes hydrolytic de-esterification to lactic acid, a normal product of muscle metabolism. PGA is chemically related to PLA and is commonly used for absorbable surgical sutures, as is the PLA/PGA copolymer. However, the use of PGA in controlled-release implants has been limited due to its low solubility in common solvents and subsequent difficulty in fabrication of devices.” The polymeric material 14 may be a biodegradable polymeric material.

U.S. Pat. No. 5,176,907 also discloses “An advantage of a biodegradable material is the elimination of the need for surgical removal after it has fulfilled its mission. The appeal of such a material is more than simply for convenience. From a technical standpoint, a material which biodegrades gradually and is excreted over time can offer many unique advantages.”

U.S. Pat. No. 5,176,907 also discloses “A biodegradable thereapeutic agent delivery system has several additional advantages: 1) the therapeutic agent release rate is amenable to control through variation of the matrix composition; 2) implantation can be done at sites difficult or impossible for retrieval; 3) delivery of unstable therapeutic agents is more practical. This last point is of particular importance in light of the advances in molecular biology and genetic engineering which have lead to the commercial availability of many potent bio-macromolecules. The short in vivo half-lives and low GI tract absorption of these polypeptides render them totally unsuitable for conventional oral or intravenous administration. Also, because these substances are often unstable in buffer, such polypeptides cannot be effectively delivered by pumping devices.”

U.S. Pat. No. 5,176,907 also discloses “In its simplest form, a biodegradable therapeutic agent delivery system consist of a dispersion of the drug solutes in a polymer matrix. The therapeutic agent is released as the polymeric matrix decomposes, or biodegrades into soluble products which are excreted from the body. Several classes of synthetic polymers, including polyesters (Pitt, et al., in Controlled Release of Bioactive Materials, R. Baker, Ed., Academic Press, New York, 1980); polyamides (Sidman, et al., Journal of Membrane Science, 7:227, 1979); polyurethanes (Maser, et al., Journal of Polymer Science, Polymer Symposium, 66:259, 1979); polyorthoesters (Heller, et al., Polymer Engineering Science, 21:727, 1981); and polyanhydrides (Leong, et al., Biomaterials, 7:364, 1986) have been studied for this purpose.” The “therapeutic agent” used in this (and other) patents may be the anti-mitotic compound of this invention.

By way of yet further illustration, and referring to U.S. Pat. No. 5,194,581 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may the poly (phosphoester) compositions described in such patent.

The polymeric material may be in the form of microcapsules within which the anti-mitotic compound of this invention is disposed. Thus, one may use microcapusels such as, e.g., the microcapsule described in U.S. Pat. No. 6,117,455, the entire disclosure of which is hereby incorporated by reference into this specification. As is disclosed in the abstract of this patent, there is provided “A sustained-release microcapsule contains an amorphous water-soluble pharmaceutical agent having a particle size of from 1 nm-10 μm and a polymer. The microcapsule is produced by dispersing, in an aqueous phase, a dispersion of from 0.001-90% (w/w) of an amorphous water-soluble pharmaceutical agent in a solution of a polymer having a wt. avg. molecular weight of 2,000-800,000 in an organic solvent to prepare an s/o/w emulsion and subjecting the emulsion to in-water drying.”

In one embodiment, disclosed in U.S. Pat. No. 5,484,584 (the entire disclosure of which is hereby incorporated by reference into this specification), a poly (benzyl-L-glutamate) microsphere is disclosed (see, e.g., claim 10); the anti-mitotic compound of this invention may be disposed within and/or on the surface of such microsphere. As is disclosed in the abstract of this patent, “The present invention relates to a highly efficient method of preparing modified microcapsules exhibiting selective targeting. These microcapsules are suitable for encapsulation surface attachment of therapeutic and diagnostic agents. In one aspect of the invention, surface charge of the polymeric material is altered by conjugation of an amino acid ester to the providing improved targeting of encapsulated agents to specific tissue cells. Examples include encapsulation of radiodiagnostic agents in 1 μm capsules to provide improved opacification and encapsulation of cytotoxic agents in 100 μm capsules for chemoembolization procedures. The microcapsules are suitable for attachment of a wide range of targeting agents, including antibodies, steroids and drugs, which may be attached to the microcapsule polymer before or after formation of suitably sized microcapsules. The invention also includes microcapsules surface modified with hydroxyl groups. Various agents such as estrone may be attached to the microcapsules and effectively targeted to selected organs.”

The release rate of the anti-mitotic compound from the polymeric material may be varied in, e.g., the manner suggested in column 6 of U.S. Pat. No. 5,194,581, the entire disclosure of which is hereby incorporated by reference into this specification. As is disclosed in such column 6, “A wide range of degradation rates can be obtained by adjusting the hydrophobicities of the backbones of the polymers and yet the biodegradability is assured. This can be achieved by varying the functional groups R or R′. The combination of a hydrophobic backbone and a hydrophilic linkage also leads to heterogeneous degradation as cleavage is encouraged, but water penetration is resisted.” As is disclosed at column 9 of such patent, “The rate of biodegradation of the poly(phosphoester) compositions of the invention may also be controlled by varying the hydrophobicity of the polymer. The mechanism of predictable degradation preferably relies on either group R′ in the poly(phosphoester) backbone being hydrophobic for example, an aromatic structure, or, alternatively, if the group R′ is not hydrophobic, for example an aliphatic group, then the group R is preferably aromatic. The rates of degradation for each poly(phosphoester) composition are generally predictable and constant at a single pH. This permits the compositions to be introduced into the individual at a variety of tissue sites. This is especially valuable in that a wide variety of compositions and devices to meet different, but specific, applications may be composed and configured to meet specific demands, dimensions, and shapes—each of which offers individual, but different, predictable periods for degradation. When the composition of the invention is used for long term delivery of a anti-mitotic compound a relatively hydrophobic backbone matrix, for example, containing bisphenol A, is preferred. It is possible to enhance the degradation rate of the poly(phosphoester) or shorten the functional life of the device, by introducing hydrophilic or polar groups, into the backbone matrix. Further, the introduction of methylene groups into the backbone matrix will usually increase the flexibility of the backbone and decrease the crystallinity of the polymer. Conversely, to obtain a more rigid backbone matrix, for example, when used orthopedically, an aromatic structure, such as a diphenyl group, can be incorporated into the matrix. Also, the poly(phosphoester) can be crosslinked, for example, using 1,3,5-trihydroxybenzene or (CH2 OH)4 C, to enhance the modulus of the polymer. Similar considerations hold for the structure of the side chain (R).”

,By way of yet further illustration, and referring to U.S. Pat. No. 5,252,713 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be a polypeptide comprising at least one drug-binding domain that non-covalently binds a drug. The means of identifying and isolating such a polypeptide is described at columns 5-7 of the patent, wherein it is disclosed that: “The process of isolating a polymeric carrier from a drug-binding, large molecular weight protein begins with the identification of a large protein that can non-covalently bind the drug of interest. Examples of such protein/drug pairs are shown in Table I. The drugs in the Table (other than the steroids) are anti-cancer drugs . . . ”

As is also disclosed in U.S. Pat. No. 5,252,713, “Other drug-binding proteins may be identified by appropriate analytical procedures, including Western blotting of large proteins or protein fragments and subsequent incubation with a detectable form of drug. Alternative procedures include combining a drug and a protein in a solution, followed by size exclusion HPLC gel filtration, thin-layer chromatography (TLC), or other analytical procedures that can discriminate between free and protein-bound drug. Detection of drug binding can be accomplished by using radiolabeled, fluorescent, or colored drugs and appropriate detection methods. Equilibrium dialysis with labeled drug may be used. Alternative methods include monitoring the fluorescence change that occurs upon binding of certain drugs (e.g., anthracyclines or analogs thereof, which should be fluorescent) . . . ”. In one detection method, drug and protein are mixed, and an aliquot of this solution (not exceeding 5% of the column volume of an HPLC column, such as a Bio-sil TSK-250 7.5×30 cm column) is loaded onto the HPLC column. The flow rate is 1 ml/min. The drug bound to protein will elute first, in a separate peak, followed by free drug, eluting at a position characteristic of its molecular weight. If the drug is doxorubicin, both a 280-nm as well as a 495-nm adsorptive peak will correspond to the elution position of the protein if interaction occurs. The elution peaks for other drugs will indicate whether drug binding occurs . . . ”

As is also disclosed in U.S. Pat. No. 5,252,713, “Knowledge of the chemical structure of a particular drug (i.e., whether chemically reactive functional groups are present) allows one to predict whether covalent binding of the drug to a given protein can occur. Additional methods for determining whether drug binding is covalent or non-covalent include incubating the drug with the protein, followed by dialysis or subjecting the protein to denaturing conditions. Release of the drug from the drug-binding protein during these procedures indicates that the drug was non-covalently bound. Usually, a dissociation constant of about 10-15 M or less indicates covalent or extremely tight non-covalent binding . . . ”

As is also disclosed in U.S. Pat. No. 5,252,713, “During dialysis, non-covalently bound drug molecules are released over time from the protein and pass through a dialysis membrane, whereas covalently bound drug molecules are retained on the protein. An equilibrium constant of about 10-5 M indicates non-covalent binding. Alternatively, the protein may be subjected to denaturing conditions; e.g., by gel electrophoresis on a denaturing (SDS) gel or on a gel filtration column in the presence of a strong denaturant such as 6M guanidine. Covalently bound drug molecules remain bound to the denatured protein, whereas non-covalently bound drug molecules are released and migrate separately from the protein on the gel and are not retained with the protein on the column.”

As is also disclosed in U.S. Pat. No. 5,252,713, “Once a protein that can non-covalently bind a particular drug of interest is identified, the drug-binding domain is identified and isolated from the protein by any suitable means. Protein domains are portions of proteins having a particular function or activity (in this case, non-covalent binding of drug molecules). The present invention provides a process for producing a polymeric carrier, comprising the steps of generating peptide fragments of a protein that is capable of non-covalently binding a drug and identifying a drug-binding peptide fragment, which is a peptide fragment containing a drug-binding domain capable of non-covalently binding the drug, for use as the polymeric carrier.”

As is also disclosed in U.S. Pat. No. 5,252,713, “One method for identifying the drug-binding domain begins with digesting or partially digesting the protein with a proteolytic enzyme or specific chemicals to produce peptide fragments. Examples of useful proteolytic enzymes include lys-C-endoprotease, arg-C-endoprotease, V8 protease, endoprolidase, trypsin, and chymotrypsin. Examples of chemicals used for protein digestion include cyanogen bromide (cleaves at methionine residues), hydroxylamine (cleaves the Asn-Gly bond), dilute acetic acid (cleaves the Asp-Pro bond), and iodosobenzoic acid (cleaves at the tryptophane residue). In some cases, better results may be achieved by denaturing the protein (to unfold it), either before or after fragmentation.”

As is also disclosed in U.S. Pat. No. 5,252,713, “The fragments may be separated by such procedures as high pressure liquid chromatography (HPLC) or gel electrophoresis. The smallest peptide fragment capable of drug binding is identified using a suitable drug-binding analysis procedure, such as one of those described above. One such procedure involves SDS-PAGE gel electrophoresis to separate protein fragments, followed by Western blotting on nitrocellulose, and incubation with a colored drug like adriamycin. The fragments that have bound the drug will appear red. Scans at 495 nm with a laser densitometer may then be used to analyze (quantify) the level of drug binding.”

As is also disclosed in U.S. Pat. No. 5,252,713, “Preferably, the smallest peptide fragment capable of non-covalent drug binding is used. It may occasionally be advisable, however, to use a larger fragment, such as when the smallest fragment has only a low-affinity drug-binding domain.”

As is also disclosed in U.S. Pat. No. 5,252,713, “The amino acid sequence of the peptide fragment containing the drug-binding domain is elucidated. The purified fragment containing the drug-binding region is denatured in 6M guanidine hydrochloride, reduced and carboxymethylated by the method of Crestfield et al., J. Biol. Chem. 238:622, 1963. As little as 20 to 50 picomoles of each peptide fragment can be analyzed by automated Edman degradation using a gas-phase or liquidpulsed protein sequencer (commercially available from Applied Biosystems, Inc.). If the peptide fragment is longer than 30 amino acids, it will most likely have to be fragmented as above and the amino acid sequence patched together from sequences of overlapping fragments.”

As is also disclosed in U.S. Pat. No. 5,252,713, “Once the amino acid sequence of the desired peptide fragment has been determined, the polymeric carriers can be made by either one of two types of synthesis. The first type of synthesis comprises the preparation of each peptide chain with a peptide synthesizer (e.g., commercially available from Applied Biosystems). The second method utilizes recombinant DNA procedures.” The polymeric material 14 may comprise one or more of the polymeric carriers described in U.S. Pat. No. 5,252,713.

As is also disclosed in U.S. Pat. No. 5,252,713, “Peptide amides can be made using 4-methylbenzhydrylamine-derivatized, cross-linked polystyrene-1% divinylbenzene resin and peptide acids made using PAM (phenylacetamidomethyl) resin (Stewart et al., “Solid Phase Peptide Synthesis,” Pierce Chemical Company, Rockford, Ill., 1984). The synthesis can be accomplished either using a commercially available synthesizer, such as the Applied Biosystems 430A, or manually using the procedure of Merrifield et al., Biochemistry 21:5020-31, 1982; or Houghten, PNAS 82:5131-35, 1985. The side chain protecting groups are removed using the Tam-Merrifield low-high HF procedure (Tam et al., J. Am. Chem. Soc. 105:6442-55, 1983). The peptide can be extracted with 20% acetic acid, lyophilized, and purified by reversed-phase HPLC on a Vydac C-4 Analytical Column using a linear gradient of 100% water to 100% acetonitrile-0.1% trifluoroacetic acid in 50 minutes. The peptide is analyzed using PTC-amino acid analysis (Heinrikson et al., Anal. Biochem. 136:65-74, 1984). After gas-phase hydrolysis (Meltzer et al., Anal. Biochem. 160: 356-61, 1987), sequences are confirmed using the Edman degradation or fast atom bombardment mass spectroscopy. After synthesis, the polymeric carriers can be tested for drug binding using size-exclusion HPLC, as described above, or any of the other analytical methods listed above.”

The polymeric carriers of U.S. Pat. No. 5,252,713 may be used with the anti-mitotic compounds of this invention. As is also disclosed in U.S. Pat. No. 5,252,713, “The polymeric carriers of the present invention preferably comprise more than one drug-binding domain. A polypeptide comprising several drug-binding domains may be synthesized. Alternatively, several of the synthesized drug-binding peptides may be joined together using bifunctional cross-linkers, as described below.” The polymeric material in one embodiment, comprises more than one drug-binding domain.

By way of yet further illustration, and referring to U.S. Pat. No. 5,420,105 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may form a conjugate with a ligand. Thus, and referring to claim 1 of such patent, such conjugate may be “A ligand or an anti-ligand/polymeric carrier/drug conjugate comprising a ligand consisting of biotin or an anti-ligand selected from the group consisting of avidin and streptavidin, which ligand or anti-ligand is covalently bound to a polymeric carrier that comprises at least one drug-binding domain derived from a drug-binding protein, and at least one drug non-covalently bound to the polymeric carrier, wherein the polymeric carrier does not comprise an entire drug-binding protein, but is derived from a drug-binding domain of said drug-binding protein which derivative non-covalently binds a drug which is non-covalently bound by an entire naturally occurring drug-binding protein, and wherein the molecular weight of the polymeric carrier is less than about 60,000 daltons, and wherein said drug is selected from the group consisting of an anti-cancer anthracycline antibiotic, cis-platinum, methotrexate, vinblastine, mitoxanthrone ARA-C, 6-mercaptopurine, 6-mercaptoguanosine, mytomycin C and a steroid.”

The polymeric material form comprise a reservoir (see U.S. Pat. No. 5,447,724) for the anti-mitotic compound(s). Such a reservoir may be constructed in accordance with the procedure described in U.S. Pat. No. 5,447,724, which claims “A medical device at least a portion of which comprises: a body insertable into a patient, said body having an exposed surface which is adapted for exposure to tissue of a patient and constructed to release, at a predetermined rate, therapeutic agent to inhibit adverse physiological reaction of said tissue to the presence of the body of said medical device, said therapeutic agent selected from the group consisting of antithrombogenic agents, antiplatelet agents, prostaglandins, thrombolytic drugs, antiproliferative drugs, antirejection drugs, antimicrobial drugs, growth factors, and anticalcifying agents, at said exposed surface, said body including: an outer polymer metering layer, and an internal polymer layer underlying and supporting said outer polymer metering layer and in intimate contact therewith, said internal polymer layer defining a reservoir for said therapeutic agent, said reservoir formed by a polymer selected from the group consisting of polyurethanes and its copolymers, silicone and its copolymers, ethylene vinylacetate, thermoplastic elastomers, polyvinylchloride, polyolefins, cellulosics, polyamides, polytetrafluoroethylenes, polyesters, polycarbonates, polysulfones, acrylics, and acrylonitrile butadiene styrene copolymers, said outer polymer metering layer having a stable, substantially uniform, predetermined thickness covering the underlying reservoir so that no portion of the reservoir is directly exposed to body fluids and incorporating a distribution of an elutable component which, upon exposure to body fluid, elutes from said outer polymer metering layer to form a predetermined porous network capable of exposing said anti-mitotic compound in said reservoir in said internal polymer layer to said body fluid, said elutable component is selected from the group consisting of polyethylene oxide, polyethylene glycol, polyethylene oxide/polypropylene oxide copolymers, polyhydroxyethylmethacrylate, polyvinylpyrollidone, polyacrylamide and its copolymers, liposomes, albumin, dextran, proteins, peptides, polysaccharides, polylactides, polygalactides, polyanhydrides, polyorthoesters and their copolymers, and soluble cellulosics, said reservoir defined by said internal polymer layer incorporating said therapeutic agent in a manner that permits substantially free outward release of said therapeutic agent from said reservoir into said porous network of said outer polymer metering layer as said elutable component elutes from said polymer metering layer, said predetermined thickness and the concentration and particle size of said elutable component being selected to enable said outer polymer metering layer to meter the rate of outward migration of the thereapuetic agent from said internal reservoir layer through said outer polymer metering layer, said outer polymer metering layer and said internal polymer layer, in combination, enabling prolonged controlled release, at said predetermined rate, of said therapeutic agent at an effective dosage level from said exposed surface of said body of said medical device to the tissue of said patient to inhibit adverse reaction of the patient to the prolonged presence of said body of said medical device in said patient.”

U.S. Pat. No. 5,447,724 also discloses the preparation of the “reservoir” in e.g., in columns 8 and 9 of the patent, wherein it is disclosed that: “A particular advantage of the time-release polymers of the invention is the manufacture of coated articles, i.e., medical instruments. Referring now to FIG. 3, the article to be coated such as a catheter 50 may be mounted on a mandrel or wire 60 and aligned with the preformed apertures 62 (slightly larger than the catheter diameter) in the teflon bottom piece 63 of a boat 64 that includes a mixture 66 of polymer at ambient temperature, e.g., 25° C. To form the reservoir portion, the mixture may include, for example, nine parts solvent, e.g. tetrahydrofuran (THF), and one part Pellthane® polyurethane polymer which includes the desired proportion of ground sodium heparin particles. The boat may be moved in a downward fashion as indicated by arrow 67 to produce a coating 68 on the exterior of catheter 50. After a short (e.g., 15 minutes) drying period, additional coats may be added as desired. After coating, the catheter 50 is allowed to air dry at ambient temperature for about two hours to allow complete solvent evaporation and/or polymerization to form the reservoir portion. For formation of the surface-layer the boat 64 is cleaned of the reservoir portion mixture and filled with a mixture including a solvent, e.g. THF (9 parts) and Pellthane® (1 part) having the desired amount of elutable component. The boat is moved over the catheter and dried, as discussed above to form the surface-layer. Subsequent coats may also be formed. An advantage of the dipping method and apparatus described with regard to FIG. 3 is that highly uniform coating thickness may be achieved since each portion of the substrate is successively in contact with the mixture for the same period of time and further, no deformation of the substrate occurs. Generally, for faster rates of movement of the boat 64, thicker layers are formed since the polymer gels along the catheter surfaces upon evaporation of the solvent, rather than collects in the boat as happens with slower boat motion. For thin layers, e.g., on the order of a few mils, using a fairly volatile solvent such as THF, the dipping speed is generally between 26 to 28 cm/min for the reservoir portion and around 21 cm/min for the outer layer for catheters in the range of 7 to 10 F. The thickness of the coatings may be calculated by subtracting the weight of the coated catheter from the weight of the uncoated catheter, dividing by the calculated surface area of the uncoated substrate and dividing by the known density of the coating. The solvent may be any solvent that solubilizes the polymer and preferably is a more volatile solvent that evaporates rapidly at ambient temperature or with mild heating. The solvent evaporation rate and boat speed are selected to avoid substantial solubilizing of the catheter substrate or degradation of a prior applied coating so that boundaries between layers are formed.”

By way of yet further illustration, and referring to U.S. Pat. No. 5,464,650 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be one or ore of the polymeric materials discussed at columns 4 and 5 of such patent. Referring to such columns 4 and 5, it is disclosed that: “The polymer chosen must be a polymer that is biocompatible and minimizes irritation to the vessel wall when the stent is implanted. The polymer may be either a biostable or a bioabsorbable polymer depending on the desired rate of release or the desired degree of polymer stability, but a bioabsorbable polymer is probably more desirable since, unlike a biostable polymer, it will not be present long after implantation to cause any adverse, chronic local response. Bioabsorbable polymers that could be used include poly(L-lactic acid), polycaprolactone, poly(lactide-co-glycolide), poly(hydroxybutyrate), poly(hydroxybutyrate-co-valerate), polydioxanone, polyorthoester, polyanhydride, poly(glycolic acid), poly(D,L-lactic acid), poly(glycolic acid-co-trimethylene carbonate), polyphosphoester, polyphosphoester urethane, poly(amino acids), cyanoacrylates, poly(trimethylene carbonate), poly(iminocarbonate), copoly(ether-esters) (e.g. PEO/PLA), polyalkylene oxalates, polyphosphazenes and biomolecules such as fibrin, fibrinogen, cellulose, starch, collagen and hyaluronic acid. Also, biostable polymers with a relatively low chronic tissue response such as polyurethanes, silicones, and polyesters could be used and other polymers could also be used if they can be dissolved and cured or polymerized on the stent such as polyolefins, polyisobutylene and ethylene-alphaolefin copolymers; acrylic polymers and copolymers, vinyl halide polymers and copolymers, such as polyvinyl chloride; polyvinyl ethers, such as polyvinyl methyl ether; polyvinylidene halides, such as polyvinylidene fluoride and polyvinylidene chloride; polyacrylonitrile, polyvinyl ketones; polyvinyl aromatics, such as polystyrene, polyvinyl esters, such as polyvinyl acetate; copolymers of vinyl monomers with each other and olefins, such as ethylene-methyl methacrylate copolymers, acrylonitrile-styrene copolymers, ABS resins, and ethylene-vinyl acetate copolymers; polyamides, such as Nylon 66 and polycaprolactam; alkyd resins; polycarbonates; polyoxymethylenes; polyimides; polyethers; epoxy resins, polyurethanes; rayon; rayon-triacetate; cellulose, cellulose acetate, cellulose butyrate; cellulose acetate butyrate; cellophane; cellulose nitrate; cellulose propionate; cellulose ethers; and carboxymethyl cellulose. The ratio of therapeutic substance to polymer in the solution will depend on the efficacy of the polymer in securing the therapeutic substance onto the stent and the rate at which the coating is to release the therapeutic substance to the tissue of the blood vessel. More polymer may be needed if it has relatively poor efficacy in retaining the therapeutic substance on the stent and more polymer may be needed in order to provide an elution matrix that limits the elution of a very soluble therapeutic substance. A wide ratio of therapeutic substance to polymer could therefore be appropriate and could range from about 10:1 to about 1:100.”

By way of yet further illustration, and referring to U.S. Pat. No. 5,470,307 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may a synthetic or natural polymer, such as polyamide, polyester, polyolefin (polypropylene or polyethylene), polyurethane, latex, acrylamide, methacrylate, polyvinylchloride, polysuflone, and the like; see, e.g., column 11 of the patent.

In one embodiment, the polymeric material is bound to the anti-mitotic compound by one or more photosensitive linkers. The process of preparing and binding these photosensitive linkers is described in columns 8-9 of U.S. Pat. No. 5,470,307, wherein it is disclosed that: “The process of fabricating a catheter 10 having a desired therapeutic agent 20 connected thereto and then controllably and selectively releasing that therapeutic agent 20 at a remote site within a patient may be summarized in five steps. 1. Formation of Substrate. The substrate layer 16 is formed on or applied to the surface 14 of the catheter body 12, and subsequently or simultaneously prepared for coupling to the linker layer 18. This is accomplished by modifying the substrate layer 16 to expose or add groups such as carboxyls, amines, hydroxyls, or sulflhydryls. In some cases, this may be followed by customizing the substrate layer 16 with an extender 22 that will change the functionality, for example by adding a maleimide group that will accept a Michael's addition of a sulfhydryl at one end of a bifunctional photolytic linker 18. The extent of this derivitization is measured by adding group-specific probes (such as 1 pyrenyl diazomethane for carboxyls, 1 pyrene butyl hydrazine for amines, or Edman's reagent for sulfhydryls Molecular Probes, Inc. of Eugene, Oreg. or Pierce Chemical of Rockford, Ill.) or other fluorescent dyes that may be measured optically or by flow cytometry. The substrate layer 16 can be built up to increase its capacity by several methods, examples of which are discussed below.”

As is also dislosed in United Sttes patent 5,470,307, “2. Selection of Photolytic Release Mechanism. A heterobifunctional photolytic linker 18 suitable for the selected therapeutic agent d20 and designed to couple readily to the functionality of the substrate layer 16 is prepared, and may be connected to the substrate layer 16. Alternately, the photolinker 18 may first be bonded to the therapeutic agent 20, with the combined complex of the therapeutic agent 20 and photolytic linker 18 together being connected to the substrate layer 16. 3. Selection of the Therapeutic Agent. Selection of the appropriate therapeutic agent 20 for a particular clinical application will depend upon the prevailing medical practice. One representative example described below for current use in PTCA and PTA procedures involves the amine terminal end of a twelve amino acid peptide analogue of hirudin being coupled to a chloro carbonyl group on the photolytic linker 18. Another representative example is provided below where the therapeutic agent 20 is a nucleotide such as an antisense oligodeoxynucleotide where a terminal phosphate is bonded by means of a diazoethane located on the photolytic linker 18. A third representative example involves the platelet inhibitor dipyridamole (persantin) that is attached through an alkyl hydroxyl by means of a diazo ethane on the photolytic linker 18. 4. Fabrication of the Linker-Agent Complex and Attachment to the Substrate. The photolytic linker 18 or the photolytic linker 18 with the therapeutic agent 20 attached are connected to the substrate layer 16 to complete the catheter 10. A representative example is a photolytic linker 18 having a sulfhydryl disposed on the non-photolytic end for attachment to the substrate layer 16, in which case the coupling will occur readily in a neutral buffer solution to a maleimide-modified substrate layer 16 on the catheter 10. Once the therapeutic agent 20 has been attached to the catheter 10, it is necessary that the catheter 10 be handled in a manner that prevents damage to the substrate layer 16, photolytic linker layer 18, and therapeutic agent 20, which may include subsequent sterilization, protection from ambient light, heat, moisture, and other environmental conditions that would adversely affect the operation or integrity of the drug-delivery catheter system 10 when used to accomplish a specific medical procedure on a patient.”

In the process of U.S. Pat. No. 5,470,307, the linker is preferably bound to the polymeric material through a modified functional group. The preparation of such modified functional groups is discussed at columns 10-13 of such patent, wherein it is disclosed that: “Most polymers including those discussed herein can be made of materials which have modifiable functional groups or can be treated to expose such groups. Polyamide (nylon) can be modified by acid treatment to produce exposed amines and carboxyls. Polyethylene terephthalate (PET, Dacron®) is a polyester and can be chemically treated to expose hydroxyls and carboxyls. Polystyrene has an exposed phenyl group that can be derivitized. Polyethylene and polypropylene (collectively referred to as polyolefins) have simple carbon backbones which can be derivitized by treatment with chromic and nitric acids to produce carboxyl functionality, photocoupling with suitably modified benzophenones, or by plasma grafting of selected monomers to produce the desired chemical functionality. For example, grafting of acrylic acid will produce a surface with a high concentration of carboxyl groups, whereas thiophene or 1,6 diaminocyclohexane will produce a surface containing sulfhydryls or amines, respectively. The surface functionality can be modified after grafting of a monomer by addition of other functional groups. For example, a carboxyl surface can be changed to an amine by coupling 1,6 diamino hexane, or to a sulfhydryl surface by coupling mercapto ethyl amine.”

As is also disclosed in United Sttes patent 5,470,307, “Acrylic acid can be polymerized onto latex, polypropylene, polysulfone, and polyethylene terephthalate (PET) surfaces by plasma treatment. When measured by toluidine blue dye binding, these surfaces show intense modification. On polypropylene microporous surfaces modified by acrylic acid, as much as 50 nanomoles of dye binding per cm2 of external surface area can be found to represent carboxylated surface area. Protein can be linked to such surfaces using carbonyl diimidazole (CDI) in tetrahydrofuran as a coupling system, with a resultant concentration of one nanomole or more per cm2 of external surface. For a 50,000 Dalton protein, this corresponds to 50 μg per cm2, which is far above the concentration expected with simple plating on the surface. Such concentrations of a anti-mitotic compound20 on the angioplasty (PTCA) balloon of a catheter 10, when released, would produce a high concentration of that therapeutic agent 20 at the site of an expanded coronary artery. However, plasma-modified surfaces are difficult to control and leave other oxygenated carbons that may cause undesired secondary reactions.”

As is also disclosed in U.S. Pat. No. 5,470,307, “In the case of balloon dilation catheters 10, creating a catheter body 12 capable of supporting a substrate layer 16 with enhanced surface area can be done by several means known to the art including altering conditions during balloon spinning, doping with appropriate monomers, applying secondary coatings such as polyethylene oxide hydrogel, branched polylysines, or one of the various Starburst.™ dendrimers offered by the Aldrich Chemical Company of Milwaukee, Wis.”

As is also disclosed in U.S. Pat. No. 5,470,307, “The most likely materials for the substrate layer 16 in the case of a dilation balloon catheter 10 or similar apparatus are shown in FIGS. 1a-1g, including synthetic or natural polymers such as polyamide, polyester, polyolefin (polypropylene or polyethylene), polyurethane, and latex. For solid support catheter bodies 12, usable plastics might include acrylamides, methacrylates, urethanes, polyvinylchloride, polysulfone, or other materials such as glass or quartz, which are all for the most part derivitizable.” In one embodiment, depicted in FIG. 1A, the photosensitive linker is bonded to a plastic container 12.

As is also disclosed in U.S. Pat. No. 5,470,307, “Referring to the polymers shown in FIGS. 1a-1g, polyamide (nylon) is treated with 3-5M hydrochloric acid to expose amines and carboxyl groups using conventional procedures developed for enzyme coupling to nylon tubing. A further description of this process may be obtained from Inman, D. J. and Hormby, W. E., The Iramobilization of Enzymes on Nylon Structures and their Use in Automated Analysis, Biochem. J. 129:255-262 (1972) and Daka, N. J. and Laidler, Flow kinetics of lactate dehydrogenase chemically attached to nylon tubing, K. J., Can. J. Biochem. 56:774-779 (1978). This process will release primary amines and carboxyls. The primary amine group can be used directly, or succinimidyl 4 (p-maleimidophenyl) butyrate (SMBP) can be coupled to the amine function leaving free the maleimide to couple with a sulfhydryl on several of the photolytic linkers 18 described below and acting as an extender 22. If needed, the carboxyl released can also be converted to an amine by first protecting the amines with BOC groups and then coupling a diamine to the carboxyl by means of carbonyl diimidazole (CDI).” The polymeric material 14, and/or the container 12, may comprise or consist essentially of nylon.

As is also disclosed in U.S. Pat. No. 5,470,307, “Polyester (Dacron®) can be functionalized using 0.01N NaOH in 10% ethanol to release hydroxyl and carboxyl groups in the manner described by Blassberger, D. et al, Chemically Modified Polyesters as Supports for Enzyme Iramobilization: Isocyanide, Acylhydrazine, and Aminoaryl derivatives of Poly(ethylene Terephthalate), Biotechnol. and Bioeng. 20:309-315 (1978). A diamine is added directly to the etched surface using CDI and then reacted with SMBP to yield the same maleimide reacting group to accept the photolytic linker 18.” The polymeric material 14, and/or the container 12, may comprise or consist essentially of polyester.”

As is also disclosed in U.S. Pat. No. 5,470,307, “Polystyrene can be modified many ways, however perhaps the most useful process is chloromethylation, as originally described by Merrifield, R. B., Solid Phase Synthesis. I. The Synthesis of a Tetrapeptide, J. Am. Chem Soc. 85:2149-2154 (1963), and later discussed by Atherton, E. and Sheppard, R. C., Solid Phase Peptide Synthesis: A Practical Approach, pp. 13-23, (IRL Press 1989). The chlorine can be modified to an amine by reaction with anhydrous ammonia.” The polymeric material may be comprised of or consist essentially of polystyrene.

As is also disclosed in U.S. Pat. No. 5,470,307, “Polyolefins (polypropylene or polyethylene) require different approaches because they contain primarily a carbon backbone offering no native functional groups. One suitable approach is to add carboxyls to the surface by oxidizing with chromic acid followed by nitric acid as described by Ngo, T. T. et al., Kinetics of acetylcholinesterase immobilized on polyethylene tubing, Can. J. Biochem. 57:1200-1203 (1979). These carboxyls are then converted to amines by reacting successively with thionyl chloride and ethylene diamine. The surface is then reacted with SMBP to produce a maleimide that will react with the sulflhydryl on the photolytic linker 18.” The polymeric material may be comprised of or consist essentially of polyolefin material.

As is also disclosed in U.S. Pat. No. 5,470,307, “A more direct method is to react the polyolefin surfaces with benzophenone 4-maleimide as described by Odom, O. W. et al, Relaxation Time, Interthiol Distance, and Mechanism of Action of Ribosomal Protein S1, Arch. Biochem Biophys. 230:178-193 (1984), to produce the required group for the sulfhydryl addition to the photolytic linker 18. The benzophenone then links to the polyolefin through exposure to ultraviolet (uv) light. Other methods to derivitize the polyolefin surface include the use of radio frequency glow discharge (RFGD)—also known as plasma discharge—in several different manners to produce an in-depth coating to provide functional groups as well as increasing the effective surface area. Polyethylene oxide (PEO) can be crosslinked to the surface, or polyethylene glycol (PEG) can also be used and the mesh varied by the size of the PEO or PEG. This is discussed more fully by Sheu, M. S., et al., A glow discharge treatment to immobilize poly(ethylene oxide)/poly(propylene oxide) surfactants for wettable and non-fouling biomaterials, J. Adhes. Sci. Tech., 6:995-1009 (1992) and Yasuda, H., Plasma Polymerization, (Academic Press, Inc. 1985). Exposed hydroxyls can be activated by tresylation, also known as trifluoroethyl sulfonyl chloride activation, in the manner described by Nielson, K. and Mosbach, K., Tresyl Chloride-Activated Supports for Enzyme Immobilization (and related articles), Meth. Enzym., 135:65-170 (1987). The function can be converted to amines by addition of ethylene diamine or other aliphatic diamines, and then the usual addition of SMBP will give the required maleimide. Another suitable method is to use RFGD to polymerize acrylic acid or other monomers on the surface of the polyolefin. This surface consisting of carboxyls and other carbonyls is derivitizable with CDI and a diamine to give an amine surface which then can react with SMBP.”

Referring again to the process described in U.S. Pat. No. 5,470,307, photolytic linkers can be conjugated to the functional groups on substrate layers to form linker-agent complexes. As is disclosed in columns 13-14 of such patent, “Once a particular functionality for the substrate layer 16 has been determined, the appropriate strategy for coupling the photolytic linker 18 can be selected and employed. Several such strategies are set out in the examples which follow. As with selecting a method to expose a functional group on the surface 14 of the substrate layer 16, it is understood that selection of the appropriate strategy for coupling the photolytic linker 18 will depend upon various considerations including the chemical functionality of the substrate layer 16, the particular therapeutic agent 20 to be used, the chemical and physical factors affecting the rate and equilibrium of the particular photolytic release mechanism, the need to minimize any deleterious side-effects that might result (such as the production of antagonistic or harmful chemical biproducts, secondary chemical reactions with adjunct medical instruments including other portions of the catheter 10, unclean leaving groups or other impurities), and the solubility of the material used to fabricate the catheter body 12 or substrate layer 16 in various solvents. More limited strategies are available for the coupling of a 2-nitrophenyl photolytic linker 18. If the active site is 1-ethyl hydrazine used in most caging applications, then the complementary functionality on the therapeutic agent 20 will be a carboxyl, hydroxyl, or phosphate available on many pharmaceutical drugs. If a bromomethyl group is built into the photolytic linker 18, it can accept either a carboxyl or one of many other functional groups, or be converted to an amine which can then be further derivitized. In such a case, the leaving group might not be clean and care must be taken when adopting this strategy for a particular anti-mitotic compound20. Other strategies include building in an oxycarbonyl in the 1-ethyl position, which can form an urethane with an amine in the anti-mitotic compound20. In this case, the photolytic process evolves CO2.”

Referring again to U.S. Pat. No. 5,470,307, after the photolytic linker construct has been prepared, it may be contacted with a coherent laser light source to release the therapeutic agent. Thus, as is disclosed in column 9 of U.S. Pat. No. 5,470,307, “use of a coherent laser light source 26 will be preferable in many applications because the use of one or more discrete wavelengths of light energy that can be tuned or adjusted to the particular photolytic reaction occurring in the photolytic linker 18 will necessitate only the minimum power (wattage) level necessary to accomplish a desired release of the anti-mitotic compound20. As discussed above, coherent or laser light sources 26 are currently used in a variety of medical procedures including diagnostic and interventional treatment, and the wide availability of laser sources 26 and the potential for redundant use of the same laser source 26 in photolytic release of the therapeutic agent 20 as well as related procedures provides a significant advantage. In addition, multiple releases of different therapeutic agents 20 or multiple-step reactions can be accomplished using coherent light of different wavelengths, intermediate linkages to dye filters may be utilized to screen out or block transmission of light energy at unused or antagonistic wavelengths (particularly cytotoxic or cytogenic wavelengths), and secondary emitters may be utilized to optimize the light energy at the principle wavelength of the laser source 26. In other applications, it may be suitable to use a light source 26 such as a flash lamp operatively connected to the portion of the body 12 of the catheter 10 on which the substrate 16, photolytic linker layer 18, and anti-mitotic compound20 are disposed. One example would be a mercury flash lamp capable of producing long-wave ultra-violet (uv) radiation within or across the 300-400 nanometer wavelength spectrum. When using either a coherent laser light source 26 or an alternate source 26 such as a flash lamp, it is generally preferred that the light energy be transmitted through at least a portion of the body 12 of the catheter 10 such that the light energy traverses a path through the substrate layer 16 to the photolytic linker layer 18 in order to maximize the proportion of light energy transmitted to the photolytic linker layer 18 and provide the greatest uniformity and reproducibility in the amount of light energy (photons) reaching the photolytic linker layer 18 from a specified direction and nature. Optimal uniformity and reproducibility in exposure of the photolyric linker layer 18 permits advanced techniques such as variable release of the anti-mitotic compound20 dependent upon the controlled quantity of light energy incident on the substrate layer 16 and photolytic linker layer 18.”

As is also disclosed in U.S. Pat. No. 5,470,307, “The art pertaining to the transmission of light energy through fiber optic conduits 28 or other suitable transmission or production means to the remote biophysical site is extensively developed. For a fiber optic device, the fiber optic conduit 28 material must be selected to accommodate the wavelengths needed to achieve release of the anti-mitotic compound20 which will for almost all applications be within the range of 280-400 nanometers. Suitable fiber optic materials, connections, and light energy sources 26 may be selected from those currently available and utilized within the biomedical field. While fiber optic conduit 28 materials may be selected to optimize transmission of light energy at certain selected wavelengths for desired application, the construction of a catheter 10 including fiber optic conduit 28 materials capable of adequate transmission throughout the range of the range of 280-400 nanometers is preferred, since this catheter 10 would be usable with the full compliment of photolytic release mechanisms and therapeutic agents 10. Fabrication of the catheter 10 will therefore depend more upon considerations involving the biomedical application or procedure by which the catheter 10 will be introduced or implanted in the patient, and any adjunct capabilities which the catheter 10 must possess.”

By way of yet further illustration, and referring to U.S. Pat. No. 5,599,352 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material can comprise fibrin. As is disclosed in column 4 of such patent, “The present invention provides a stent comprising fibrin. The term “fibrin” herein means the naturally occurring polymer of fibrinogen that arises during blood coagulation. Blood coagulation generally requires the participation of several plasma protein coagulation factors: factors XII, XI, IX, X, VIII, VII, V, XIII, prothrombin, and fibrinogen, in addition to tissue factor (factor III), kallikrein, high molecular weight kininogen, Ca+2, and phospholipid. The final event is the formation of an insoluble, cross-linked polymer, fibrin, generated by the action of thrombin on fibrinogen. Fibrinogen has three pairs of polypeptide chains (ALPHA 2—BETA 2—GAMMA 2) covalently linked by disulfide bonds with a total molecular weight of about 340,000. Fibrinogen is converted to fibrin through proteolysis by thrombin. An activation peptide, fibrinopeptide A (human) is cleaved from the amino-terminus of each ALPHA chain; fibrinopeptide B (human) from the amino-terminus of each BETA chain. The resulting monomer spontaneously polymerizes to a fibrin gel. Further stabilization of the fibrin polymer to an insoluble, mechanically strong form, requires cross-linking by factor XIII. Factor XIII is converted to XIIIa by thrombin in the presence of Ca+2. XIIIa cross-links the GAMMA chains of fibrin by transglutaminase activity, forming EPSILON-(GAMMA-glutamyl) lysine cross-links. The ALPHA chains of fibrin also may be secondarily cross-linked by transamidation.”

As is also disclosed in U.S. Pat. No. 5,599,352, “Since fibrin blood clots are naturally subject to fibrinolysis as part of the body's repair mechanism, implanted fibrin can be rapidly biodegraded. Plasminogen is a circulating plasma protein that is adsorbed onto the surface of the fibrin polymer. The adsorbed plasminogen is converted to plasmin by plasminogen activator released from the vascular endothelium. The plasmin will then break down the fibrin into a collection of soluble peptide fragments.”

As is also disclosed in U.S. Pat. No. 5,599,352, “Methods for making fibrin and forming it into implantable devices are well known as set forth in the following patents and published applications which are hereby incorporated by reference. In U.S. Pat. No. 4,548,736 issued to Muller et al., fibrin is clotted by contacting fibrinogen with a fibrinogen-coagulating protein such as thrombin, reptilase or ancrod. Preferably, the fibrin in the fibrin-containing stent of the present invention has Factor XIII and calcium present during clotting, as described in U.S. Pat. No. 3,523,807 issued to Gerendas, or as described in published European Patent Application 0366564, in order to improve the mechanical properties and biostability of the implanted device. Also preferably, the fibrinogen and thrombin used to make fibrin in the present invention are from the same animal or human species as that in which the stent of the present invention will be implanted in order to avoid cross-species immune reactions. The resulting fibrin can also be subjected to heat treatment at about 150° C. for 2 hours in order to reduce or eliminate antigenicity. In the Muller patent, the fibrin product is in the form of a fine fibrin film produced by casting the combined fibrinogen and thrombin in a film and then removing moisture from the film osmotically through a moisture permeable membrane. In the European Patent Application 0366564, a substrate (preferably having high porosity or high affinity for either thrombin or fibrinogen) is contacted with a fibrinogen solution and with a thrombin solution. The result is a fibrin layer formed by polymerization of fibrinogen on the surface of the device. Multiple layers of fibrin applied by this method could provide a fibrin layer of any desired thickness. Or, as in the Gerendas patent, the fibrin can first be clotted and then ground into a powder which is mixed with water and stamped into a desired shape in a heated mold. Increased stability can also be achieved in the shaped fibrin by contacting the fibrin with a fixing agent such as glutaraldehyde or formaldehyde. These and other methods known by those skilled in the art for making and forming fibrin may be used in the present invention.”

As is also disclosed in U.S. Pat. No. 5,599,352, “Preferably, the fibrinogen used to make the fibrin is a bacteria-free and virus-free fibrinogen such as that described in U.S. Pat. No. 4,540,573 to Neurath et al which is hereby incorporated by reference. The fibrinogen is used in solution with a concentration between about 10 and 50 mg/ml and with a pH of about 5.8-9.0 and with an ionic strength of about 0.05 to 0.45. The fibrinogen solution also typically contains proteins and enzymes such as albumin, fibronectin (0-300 μg per ml fibrinogen), Factor XIII (0-20 μg per ml fibrinogen), plasminogen (0-210 μg per ml fibrinogen), antiplasmin (0-61 μg per ml fibrinogen) and Antithrombin II (0-150 μg per ml fibrinogen). The thrombin solution added to make the fibrin is typically at a concentration of 1 to 120 NIH units/ml with a preferred concentration of calcium ions between about 0.02 and 0.2M.”

As is also disclosed in U.S. Pat. No. 5,599,352, “Polymeric materials can also be intermixed in a blend or co-polymer with the fibrin to produce a material with the desired properties of fibrin with improved structural strength. For example, the polyurethane material described in the article by Soldani et at., “Bioartificial Polymeric Materials Obtained from Blends of Synthetic Polymers with Fibrin and Collagen” International Journal of Artificial Organs, Vol. 14, No. 5, 1991, which is incorporated herein by reference, could be sprayed onto a suitable stent structure. Suitable polymers could also be biodegradable polymers such as polyphosphate ester, polyhydroxybutyrate valerate, polyhydroxybutyrate-co-hydroxyvalerate and the like . . . ” The polymeric material 14 may be, e.g., a blend of fibrin and another polymeric material.

As is also disclosed in U.S. Pat. No. 5,599,352, “The shape for the fibrin can be provided by molding processes. For example, the mixture can be formed into a stent having essentially the same shape as the stent shown in U.S. Pat. No. 4,886,062 issued to Wiktor. Unlike the method for making the stent disclosed in Wiktor which is wound from a wire, the stent made with fibrin can be directly molded into the desired open-ended tubular shape.”

As is also disclosed in U.S. Pat. No. 5,599,352, “In U.S. Pat. No. 4,548,736 issued to Muller et al., a dense fibrin composition is disclosed which can be a bioabsorbable matrix for delivery of drugs to a patient. Such a fibrin composition can also be used in the present invention by incorporating a drug or other therapeutic substance useful in diagnosis or treatment of body lumens to the fibrin provided on the stent. The drug, fibrin and stent can then be delivered to the portion of the body lumen to be treated where the drug may elute to affect the course of restenosis in surrounding luminal tissue. Examples of drugs that are thought to be useful in the treatment of restenosis are disclosed in published international patent application WO 91/12779 “Intraluminal Drug Eluting Prosthesis” which is incorporated herein by reference. Therefore, useful drugs for treatment of restenosis and drugs that can be incorporated in the fibrin and used in the present invention can include drugs such as anticoagulant drugs, antiplatelet drugs, antimetabolite drugs, anti-inflammatory drugs and antimitotic drugs. Further, other vasoreactive agents such as nitric oxide releasing agents could also be used. Such therapeutic substances can also be microencapsulated prior to their inclusion in the fibrin. The micro-capsules then control the rate at which the therapeutic substance is provided to the blood stream or the body lumen. This avoids the necessity for dehydrating the fibrin as set forth in Muller et al., since a dense fibrin structure would not be required to contain the therapeutic substance and limit the rate of delivery from the fibrin. For example, a suitable fibrin matrix for drug delivery can be made by adjusting the pH of the fibrinogen to below about pH 6.7 in a saline solution to prevent precipitation (e.g., NACl, CaCl, etc.), adding the microcapsules, treating the fibrinogen with thrombin and mechanically compressing the resulting fibrin into a thin film. The microcapsules which are suitable for use in this invention are well known. For example, the disclosures of U.S. Pat. Nos. 4,897,268, 4,675,189; 4,542,025; 4,530,840; 4,389,330; 4,622,244; 4,464,317; and 4,943,449 could be used and are incorporated herein by reference. Alternatively, in a method similar to that disclosed in U.S. Pat. No. 4,548,736 issued to Muller et al., a dense fibrin composition suitable for drug delivery can be made without the use of microcapsules by adding the drug directly to the fibrin followed by compression of the fibrin into a sufficiently dense matrix that a desired elution rate for the drug is achieved. In yet another method for incorporating drugs which allows the drug to elute at a controlled rate, a solution which includes a solvent, a polymer dissolved in the solvent and a therapeutic drug dispersed in the solvent is applied to the structural elements of the stent and then the solvent is evaporated. Fibrin can then be added over the coated structural elements in an adherent layer. The inclusion of a polymer in intimate contact with a drug on the underlying stent structure allows the drug to be retained on the stent in a resilient matrix during expansion of the stent and also slows the administration of drug following implantation. The method can be applied whether the stent has a metallic or polymeric surface. The method is also an extremely simple method since it can be applied by simply immersing the stent into the solution or by spraying the solution onto the stent. The amount of drug to be included on the stent can be readily controlled by applying multiple thin coats of the solution while allowing it to dry between coats. The overall coating should be thin enough so that it will not significantly increase the profile of the stent for intravascular delivery by catheter. It is therefore preferably less than about 0.002 inch thick and most preferably less than 0.001 inch thick. The adhesion of the coating and the rate at which the drug is delivered can be controlled by the selection of an appropriate bioabsorbable or biostable polymer and by the ratio of drug to polymer in the solution. By this method, drugs such as glucocorticoids (e.g. dexamethasone, betamethasone), heparin, hirudin, tocopherol, angiopeptin, aspirin, ACE inhibitors, growth factors, oligonucleotides, and, more generally, antiplatelet agents, anticoagulant agents, antimitotic agents, antioxidants, antimetabolite agents, and anti-inflamrnatory agents can be applied to a stent, retained on a stent during expansion of the stent and elute the drug at a controlled rate. The release rate can be further controlled by varying the ratio of drug to polymer in the multiple layers. For example, a higher drug-to-polymer ratio in the outer layers than in the inner layers would result in a higher early dose which would decrease over time. Examples of some suitable combinations of polymer, solvent and therapeutic substance are set forth in Table 1 below . . . ”

At column 7 of U.S. Pat. No. 5,599,352, some polymers that can be mixed with the fibrin are discussed. It is disclosed that: “The polymer used can be a bioabsorbable or biostable polymer. Suitable bioabsorbable polymers include poly(L-lactic acid), poly(lactide-co-glycolide) and poly(hydroxybutyrate-co-valerate). Suitable biostable polymers include silicones, polyurethanes, polyesters, vinyl homopolymers and copolymers, acrylate homopolymers and copolymers, polyethers and cellulosics. A typical ratio of drug to dissolved polymer in the solution can vary widely (e.g. in the range of about 10:1 to 1:100). The fibrin is applied by molding a polymerization mixture of fibrinogen and thrombin onto the composite as described herein.” The polymeric material 14 may be, e.g., a blend of fibrin and a bioabsorbable and/or biostable polymer.

By way of yet further illustration, and referring to U.S. Pat. No. 5,605,696, the polymeric material can be a multi-layered polymeric material, and/or a porous polymeric material. Thus, e.g., and as is disclosed in claim 25 of such patent, “A polymeric material containing a therapeutic drug for application to an intravascular stent for carrying and delivering said therapeutic drug within a blood vessel in which said intravascular stent is placed, comprising: a polymeric material having a thermal processing temperature no greater than about 100° C.; particles of a therapeutic drug incorporated in said polymeric material; and a porosigen uniformly dispersed in said polymeric material, said porosigen being selected from the group consisting of sodium chloride, lactose, sodium heparin, polyethylene glycol, copolymers of polyethylene oxide and polypropylene oxide, and mixtures thereof.” The “porsigen” is described at columns 4 and 5 of the patent, wherein it is disclosed that: “porosigen can also be incorporated in the drug loaded polymer by adding the porosigen to the polymer along with the therapeutic drug to form a porous, drug loaded polymeric membrane. A porosigen is defined herein for purposes of this application as any moiety, such as microgranules of sodium chloride, lactose, or sodium heparin, for example, which will dissolve or otherwise be degraded when immersed in body fluids to leave behind a porous network in the polymeric material. The pores left by such porosigens can typically be a large as 10 microns. The pores formed by porosigens such as polyethylene glycol (PEG), polyethylene oxide/polypropylene oxide (PEO/PPO) copolymers, for example, can also be smaller than one micron, although other similar materials which form phase separations from the continuous drug loaded polymeric matrix and can later be leached out by body fluids can also be suitable for forming pores smaller than one micron. While it is currently preferred to apply the polymeric material to the structure of a stent while the therapeutic drug and porosigen material are contained within the polymeric material, to allow the porosigen to be dissolved or degraded by body fluids when the stent is placed in a blood vessel, alternatively the porosigen can be dissolved and removed from the polymeric material to form pores in the polymeric material prior to placement of the polymeric material combined with the stent within a blood vessel. If desired, a rate-controlling membrane can also be applied over the drug loaded polymer, to limit the release rate of the therapeutic drug. Such a rate-controlling membrane can be useful for delivery of water soluble substances where a nonporous polymer film would completely prevent diffusion of the drug. The rate-controlling membrane can be added by applying a coating from a solution, or a lamination, as described previously. The rate-controlling membrane applied over the polymeric material can be formed to include a uniform dispersion of a porosigen in the rate-controlling membrane, and the porosigen in the rate-controlling membrane can be dissolved to leave pores in the rate-controlling membrane typically as large as 10 microns, or as small as 1 micron, for example, although the pores can also be smaller than 1 micron. The porosigen in the rate-controlling membrane can be, for example, sodium chloride, lactose, sodium heparin, polyethylene glycol, polyethylene oxide/polypropylene oxide copolymers, and mixtures thereof.” The polymeric material 14 may comprise a multiplicity of layers of polymeric material.

By way of yet further illustration, and referring to U.S. Pat. No. 5,700,286 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be either a thermoplastic or an elastomeric polymer. Thus, and referring to columns 5 and 6 of such patent, “The polymeric material is preferably selected from thermoplastic and elastomeric polymers. In one currently preferred embodiment the polymeric material can be a material available under the trade name “C-Flex” from Concept Polymer Technologies of Largo, Fla. In another currently preferred embodiment, the polymeric material can be ethylene vinyl acetate (EVA); and in yet another currently preferred embodiment, the polymeric material can be a material available under the trade name “BIOSPAN.” Other suitable polymeric materials include latexes, urethanes, polysiloxanes, and modified styrene-ethylenelbutylene-styrene block copolymers (SEBS) and their associated families, as well as elastomeric, bioabsorbable, linear aliphatic polyesters. The polymeric material can typically have a thickness in the range of about 0.002 to about 0.020 inches, for example. The polymeric material is preferably bioabsorbable, and is preferably loaded or coated with a anti-mitotic compounder drug, including, but not limited to, antiplatelets, antithrombins, cytostatic and antiproliferative agents, for example, to reduce or prevent restenosis in the vessel being treated.”

By way of yet further illustration, and referring to U.S. Pat. No. 6,004,346 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be a bioabsorbable polymer. Thus, and referring to column 7 of such patent, “controlled release, via a bioabsorbable polymer, offers to maintain the drug level within the desired therapeutic range for the duration of the treatment. In the case of stents, the prosthesis materials will maintain vessel support for at least two weeks or until incorporated into the vessel wall even with bioabsorbable, biodegradable polymer constructions.”

As is also disclosed in U.S. Pat. No. 6,004,346, “Several polymeric compounds that are known to be bioabsorbable and hypothetically have the ability to be drug impregnated may be useful in prosthesis formation herein. These compounds include: poly-1-lactic acid/polyglycolic acid, polyanhydride, and polyphosphate ester. A brief description of each is given below.”

As is also disclosed in U.S. Pat. No. 6,004,346, “Poly-1-lactic acid/polyglycolic acid has been used for many years in the area of bioabsorbable sutures. It is currently available in many forms, i.e., crystals, fibers, blocks, plates, etc. . . . ”

As is also disclosed in U.S. Pat. No. 6,004,346, “Another compound which could be used are the polyanhydrides. They are currently being used with several chemotherapy drugs for the treatment of cancerous tumors. These drugs are compounded into the polymer which is molded into a cube-like structure and surgically implanted at the tumor site . . . ”

As is also disclosed in U.S. Pat. No. 6,004,346, “The compound which is preferred is a polyphosphate ester. Polyphosphate ester is a compound such as that disclosed in U.S. Pat. Nos. 5,176,907; 5,194,581; and 5,656,765 issued to Leong which are incorporated herein by reference. Similar to the polyanhydrides, polyphoshate ester is being researched for the sole purpose of drug delivery. Unlike the polyanhydrides, the polyphosphate esters have high molecular weights (600,000 average), yielding attractive mechanical properties. This high molecular weight leads to transparency, and film and fiber properties. It has also been observed that the phosphorous-carbon-oxygen plasticizing effect, which lowers the glass transition temperature, makes the polymer desirable for fabrication.”

As is also disclosed in U.S. Pat. No. 6,004,346, “The basic structure of polyphosphate ester monomer is shown below . . . where P corresponds to Phosphorous, O corresponds to Oxygen, and R and R1 are functional groups. Reaction with water leads to the breakdown of this compound into monomeric phosphates (phosphoric acid) and diols (see below). [Figure] It is the hydrolytic instability of the phosphorous ester bond which makes this polymer attractive for controlled drug release applications. A wide range of controllable degradation rates can be obtained by adjusting the hydrophobicities of the backbones of the polymers and yet assure biodegradability. he functional side groups allow for the chemical linkage of drug molecules to the polymer . . . he drug may also be incorporated into the backbone of the polymer.”

By way of further illustration, and referring to U.S. Pat. No. 6,120,536 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may comprise a hydrophobic elastomeric material incorporating an amount of anti-mitotic compound therein for timed release. Some of these elastomeric materials are described at columns 5 and 6 of such patent, wherein it is disclosed that: “The elastomeric materials that form the stent coating underlayers should possess certain properties. Preferably the layers should be of suitable hydrophobic biostable elastomeric materials which do not degrade. Surface layer material should minimize tissue rejection and tissue inflammation and permit encapsulation by tissue adjacent the stent implantation site. Exposed material is designed to reduce clotting tendencies in blood contacted and the surface is preferably modified accordingly. Thus, underlayers of the above materials are preferably provided with a fluorosilicone outer coating layer which may or may not contain imbedded bioactive material, such as heparin. Alternatively, the outer coating may consist essentially of polyethylene glycol (PEG), polysaccharides, phospholipids, or combinations of the foregoing.”

As is also disclosed in U.S. Pat. No. 6,120,536, “Polymers generally suitable for the undercoats or underlayers include silicones (e.g., polysiloxanes and substituted polysiloxanes), polyurethanes, thermoplastic elastomers in general, ethylene vinyl acetate copolymers, polyolefin elastomers, polyamide elastomers, and EPDM rubbers. The above-referenced materials are considered hydrophobic with respect to the contemplated environment of the invention. Surface layer materials include fluorosilicones and polyethylene glycol (PEG), polysaccharides, phospholipids, and combinations of the foregoing.”

As is also disclosed in U.S. Pat. No. 6,120,536, “Various combinations of polymer coating materials can be coordinated with biologically active species of interest to produce desired effects when coated on stents to be implanted in accordance with the invention. Loadings of therapeutic materials may vary. The mechanism of incorporation of the biologically active species into the surface coating and egress mechanism depend both on the nature of the surface coating polymer and the material to be incorporated. The mechanism of release also depends on the mode of incorporation. The material may elute via interparticle paths or be administered via transport or diffusion through the encapsulating material itself.”

By way of yet further illustration, and referring to U.S. Pat. No. 6,159,488 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be a biopolymer that is non-degradable and is insoluble in biological mediums. Thus, and as is disclosed at column 8 of this patent, “The polymer carrier can be any pharmaceutically acceptable biopolymer that is non-degradable and insoluble in biological mediums, has good stability in a biological environment, has a good adherence to the selected stent, is flexible, and that can be applied as coating to the surface of a stent, either from an organic solvent, or by a melt process. The hydrophilicity or hydrophobicity of the polymer carrier will determine the release rate of halofuginone from the stent surface . . . . The coating may include other antiproliferative agents, such as heparin, steroids and non-steroidal anti-inflammatory agents. To improve the blood compatibility of the coated stent, a hydrophilic coating such as hydromer-hydrophilic polyurethane can be applied. A material for delivering a biologically active compound comprising a solid carrier material having dissolved and/or dispersed therein at least two biologically active compounds, each of said at least two biologically active compounds having a biologically active nucleus which is common to each of the biologically active compounds, and the at least two biologically active compounds having maximum solubility levels in a single solvent which differ from each other by at least 10% by weight; wherein said solid carrier comprises a biocompatible polymeric material.”

By way of yet further illustration, and referring to claim 1 of U.S. Pat. No. 6,168,801 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may comprise “A material for delivering a biologically active compound comprising a solid carrier material having dissolved and/or dispersed therein at least two biologically active compounds, each of said at least two biologically active compounds having a biologically active nucleus which is common to each of the biologically active compounds, and the at least two biologically active compounds having maximum solubility levels in a single solvent which differ from each other by at least 10% by weight; wherein said solid carrier comprises a biocompatible polymeric material.”

The device of U.S. Pat. No. 6,168,801 preferably comprises at least two forms of a biologically active ingredient in a single polymeric matrix. Thus, and as is disclosed at column 6 of the patent, “It is contemplated in the practice of the present invention that the combination of the at least two forms of the biologically active ingredient or medically active ingredient in at least a single polymeric carrier can provide release of the active ingredient nucleus common to the at least two forms. The release of the active nucleus can be accomplished by, for example, enzymatic hydrolysis of the forms upon release from the carrier device. Further, the combination of the at least two forms of the biologically active ingredient or medically active ingredient in at least a single polymeric carrier can provide net active ingredient release characterized by the at least simple combination of the two matrix forms described above. This point is illustrated in FIG. 1 which compares the in vitro release of dexamethasone from matrices containing various fractions of two forms of the synthetic steroid dexamethasone, dexamethasone sodium phosphate (DSP; hydrophilic) and dexamethasone acetate (DA; hydrophobic). It is easy to see from these results that the release of dexamethasone acetate (specifically, 100% DA) is slower than all other matrices tested containing some degree or loading of dexamethasone sodium phosphate (hydrophilic). Still further, the resulting active ingredient release from the combined form matrix should be at least more rapid in the early stages of release than the slow single active ingredient component alone. Further still, the cumulative active ingredient release from the combined form matrix should be at least greater in the chronic stages than the fast single active ingredient component. Once again from FIG. 1, the two test matrices containing the greatest amount of dexamethasone sodium phosphate (specifically, 100% DSP, and 75% DSP/25% DA) began to slow in release as pointed out at points “A” and “B”. And further still, the optimal therapeutic release can be designed through appropriate combination of the at least two active biological or medical ingredients in the polymeric carrier material. If as in this example, rapid initial release as well as continuous long term release is desired to achieve a therapeutic goal, the matrix composed of 50% DSP/50% DA would be selected.”

By way of yet further illustration, and referring to claim 1 of U.S. Pat. No. 6,395,300 (the entire disclosure of which is hereby incorporated by reference into this specification), the polymeric material may be a porous polymeric matrix made by a process comprising the steps of: “a) dissolving a drug in a volatile organic solvent to form a drug solution, (b) combining at least one volatile pore forming agent with the volatile organic drug solution to form an emulsion, suspension, or second solution, and (c) removing the volatile organic solvent and volatile pore forming agent from the emulsion, suspension, or second solution to yield the porous matrix comprising drug, wherein the porous matrix comprising drug has a tap density of less than or equal to 1.0 g/mL or a total surface area of greater than or equal to 0.2 m2/g.”

The term “anti-micrtubule,” as used in this specification (and in the specification of U.S. Pat. No. 6,689,803), refers to any “ . . . protein, peptide, chemical, or other molecule which impairs the function of microtubules, for example, through the prevention or stabilization of polymerization. A wide variety of methods may be utilized to determine the anti-microtubule activity of a particular compound, including for example, assays described by Smith et al. (Cancer Lett 79(2):213-219, 1994) and Mooberry et al., (Cancer Lett. 96(2):261-266, 1995);” see, e.g., lines 13-21 of column 14 of U.S. Pat. No. 6,689,803.

An extensive listing of anti-microtubule agents is provided in columns 14, 15, 16, and 17 of U.S. Pat. No. 6,689,803; and one or more of them may be disposed within the polymeric material together with and/or instead of the anti-mitotic compound of this invention. In one embodiment, these prior art anti-microtubule agents are made magnetic in accordance with the process described earlier in this specification.

As is also disclosed in U.S. Pat. No. 6,689,893, “Representative examples of thermogelling polymers, and their gelatin temperature (LCST (° C.)) include homopolymers such as poly(-methyl-N-n-propylacrylamide), 19.8; poly(N-n-propylacrylamide), 21.5; poly(N-methyl-N-isopropylacrylamide), 22.3; poly(N-n-propylmethacrylamide), 28.0; poly(N-isopropylacrylamide), 30.9; poly(N,n-diethylacrylamide), 32.0; poly(N-isopropylmethacrylamide), 44.0; poly(N-cyclopropylacrylamide), 45.5; poly(N-ethylmethyacrylamide), 50.0; poly(N-methyl-N-ethylacrylamide), 56.0; poly(N-cyclopropylmethacrylamide), 59.0; poly(N-ethylacrylamide), 72.0. Moreover thermogelling polymers may be made by preparing copolymers between (among) monomers of the above, or by combining such homopolymers with other water soluble polymers such as acrylmonomers (e.g., acrylic acid and derivatives thereof such as methylacrylic acid, acrylate and derivatives thereof such as butyl methacrylate, acrylamide, and N-n-butyl acrylamide).”

As is also disclosed in U.S. Pat. No. 6,689,893, “Preferably, therapeutic compositions of the present invention are fashioned in a manner appropriate to the intended use. Within certain aspects of the present invention, the therapeutic composition should be biocompatible, and release one or more therapeutic agents over a period of several days to months. For example, “quick release” or “burst” therapeutic compositions are provided that release greater than 10%, 20%, or 25% (w/v) of a therapeutic agent (e.g., paclitaxel) over a period of 7 to 10 days. Such “quick release” compositions should, within certain embodiments, be capable of releasing chemotherapeutic levels (where applicable) of a desired agent. Within other embodiments, “low release” therapeutic compositions are provided that release less than 1% (w/v) of a therapeutic agent a period of 7 to 10 days. Further, therapeutic compositions of the present invention should preferably be stable for several months and capable of being produced and maintained under sterile conditions.”

In one preferred embodiment, the anti-mitotic compound is disposed on or in a drug-eluting polymer that is adapted to elute the anti-mitotic compound at a specified rate. These polymers are well known and are often used in conjunction with drug-eluting stents. Reference may be had, e.g., to U.S. Pat. Nos. 6,702,850 (multi-coated drug-eluting stent), 6,671,562 (high impedance drug eluting cardiac lead), 6,206,914, 6,004,346 (intralumenl drug eluting prosthesis), 5,997,468, 5,871,535 (intralumenal drug eluting prosthesis), 5,851,231, 5,851,217, 5,725,567, 5,697,967 (drug eluting stent), 5,599,352 (method of making a drug elting stent), 5,591,227 (drug eluting stent), 5,545,208 (intralumenal drug eluting prosthesis), 5,217,028 (bipolar cardiac lead with drug eluting device), 4,953,564 (screw-in drug eluting lead), and the like. The entire disclosure of each of these United States patents is hereby incorporated by referenc into this specification.

Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additons, substitutions, and the like can be made without departing from the spirit of the invention, and these are thus considered to be within the scope of the invnetino as defined in the claims which follow.